If you're using an oldish computer you may need to install Microsoft's .net framework. You can download it here. The editor is compiled to work from .net 2.0 upwards.
Before you start messing with your savefiles, BACK THEM UP. While the program is generally very stable, it isn't even in beta yet so it might still have some bugs that need ironing out.
Your savefiles are located in:
{SSF Folder}/Backup/Internal
{SSF Folder}/Backup/External
At time of writing, the emulator also has limited support for importing External Backup files from older version of SSF, Casini, Giri Giri and Yabause but can only save as newer SSF formats. These files are generally located in the emulator folder and have names like "ExternalBackupRam.bin".
To open a file either click File -> Open or drag the file into the editor window.
To make SSF use the new format that the editor works with, you'll need to enable Hook Backup Library in SSF's options. Upon doing this you won't have access to your savefiles in the old InternalBackupRam.bin and ExternalBackupRam.bin files, but you will get the ability to make 99 saves of every game you play.
The Main Window allows you to edit your characters' Name, Class, AI, Stats, Magic, Special Attacks, Equippable Weapons, Items and Friendships. It also lets you edit the savefile's Play Time, Difficulty Level, Current Location and the amount of Gold currently held.
To switch between characters just select the character you wish to edit from the Character dropdown box in the top left section of the window.
You can open the Force Editor by clicking Edit -> Force Roster. This window allows you to rearrange which characters are in which Forces, as well as add characters you've missed (or haven't got yet) or wouldn't normally have access to to your forces.
There are a few things to look out for when adding characters you shouldn't have access to:
Garosh: Garosh and Jade's Sprites will get mixed in the scene where Emperor Domaric visits your headquarters in Storich. This is because they're both occupying the same space. Otherwise everything works fine.
Jade: Same as with Garosh with the sprite mixing, but he will also be removed from your party and added to the enemy forces in the Headland Plains battle.
Rogan: Rogan has no Sprite defined (and the game makes an error noise whenever it tries to load it) but is otherwise perfectly useable.
Edmund: He will be added to the enemy forces when you battle him but is otherwise fine.
Produn: He will be added to the enemy forces when you battle him but is otherwise fine.
Towards the start of the games you'll also have an artificial limit on how many characters you can have in your main party. If you add more characters than this limit they will not getting added into battles. This gets increased as you play through the game.
You can open the NPC Editor by clicking Edit -> NPCs whilst a Scenario 2 or 3 file is open. This window lets you edit the Monsters and Dragons you have in your party. You can edit them to almost every enemy in the game - some of the enemies that have big 3d sprites like the Octopus and the Collosus are buggy as hell though.
In Scenario 2, the game doesn't display names correctly of NPCs that shouldn't be in a battle. If you add Garvin to your force his name display correctly, but if you add Basanda her name won't display at all. You also need to limit yourself to 2 + number of party members missed (including Jade/Garosh) Monsters otherwise the game bugs out a bit.
In Scenario 3 everything works perfectly. The only thing to note is that only 1 NPC will get added to a battle if you have 12 characters in your main force. You can free up more space for NPCs by clearing out space in your main squad using the Force Editor.
You can open the The Flag Editor by clicking Edit -> Event Flags whilst in any scenario except the Premium Disc. This window lets you edit all the Flags/Switches/Booleans that keep track of your progress through the game. You can use this to do things like skip/replay battles, change your sync points and even skip/replay scenes.
To use it, just click the tab for the Chapter you want to edit, then check/uncheck any flags you want to change then click OK when you're done.
Note: Some of the flags are set at the start of the game and get set to false as you progress through the game, so don't be alarmed if your savefile says you've saved all of the Railhead Refugees when you haven't got that far yet.
You can open the Headquarters Inventory Editor by clicking Edit -> Headquarters Inventory whilst in any scenario except the Premium Disc. This window lets you alter the quantities of each item available in your Headquarters Stored Items. The window updates the values as you edit them so just close it off when you're done.
Note: This part of the Editor is still Work In Progress and, while it works perfectly, is slow as hell and has a few display bugs with resizing etc.
This is a WIP part of the editor to edit Enemy and NPC stats whilst in a battle. It works the same as the main Character editing window and can be accessed via Edit -> Battle Stats.
So far it is possible to edit NPC Stats, Equipment, Spells, Specials, NPC Type and AI Type. If you want to make an enemy/npc player controllable set their AI Type to 0.
Note: Currently, the battle stats window picks up enemies from past battles as well as enemies from the current battle. The game doesn't bother to clear the old enemy data out of the savefile and a good way to distinguish which are active or inactive enemies hasn't been worked out yet. It is also only enabled by default in Scenario 2 and 3, as relevant data still hasn't been collected and tested for Scenario 1 and the Premium Disc.
You can access this window by clicking Edit -> Preferences. This window lets you turn on/off a few features of the editor. The options are:
Use Original Translations - Use item names closer to the original Japanese Text. If you're playing with the Shining Force 3 Translation Project it is recommended you turn this on. The changes will take effect next time you open a savefile.
Enable Reload File Button - this adds a quick reload button to the top menu strip. If you're doing some experiments on how the game works you'll probably want to turn this on.
Enable Medion in Scenario 1 - This allows you to edit Medion and add him to your force in Scenario 1; beware he is a little buggy and his stats are reset upon starting Scenario 2.
Open Last Savefile on Startup - when enabled the editor will attempt to load the last savefile it used when it is first run.