1. Make a copy of your Thief shortcut, Name it "Thief Gold FM Loader".
2. Open the shortcut's properties and add -fm to the text in the Target field. That's how it should look like:
D:\Games\ThiefG\thief.exe
modify to
D:\Games\ThiefG\thief.exe -fm
Then click OK to save changes.
3. Start the new shortcut. You'll be asked if you'd like to create the "FMs" folder. Click yes.
4. Suppress your greensy nature and click the small button with the gear icon on it. Select the "FM Archive Path..." and navigate to the folder where your Thief Gold fan-mission archives are located.
5. Select the FM in the list and click "Play FM".

1. Open the file cam_mod.ini in your Thief directory.
2. Near the beginning of the file, you'll find the line ; always start the FM Selector (if one is present), and below it you should see the line ;fm.
3. Delete the semicolon in front of ;fm and save the file.
4. Launch Thief, FMSel should launch instead.
5. You'll be asked if you'd like to create the "FMs" folder. Click yes.
6. Click the small button with the gear icon on it. Select the "FM Archive Path..." and navigate to the folder where your Thief Gold fan-mission archives are located.
7. Select the FM in the list and click "Play FM".
8. If you wish to revert back to Thief, add the semicolon in front of ;fm again.