Open Gnome Editor. Click on "load file". Locate you MTW folder. Inside the MTW main folder, the is a file called "crudaders_unit_product11.txt". It is the file you want to load for editing.

After you've done with editing, click on "save file as". You want to save edited file over the existing one (overwrite the old one) by locating the same file (that you open for edit) in the MTW folder, click on it and its name will appear as the name of the file you want to save as. Click on "save". You will be asked if you want to overwrite the existing file and you should click on "Yes".

Load default is when you need to load the default stats. You will need to save it to make it effect the game.

If you want to make further changes to the already edited file and you don't want to lose anything in case you make a mistake, you should copy the current file (crusaders_unit_prod11.txt") to some where else so you now have 2 copies of it. Do the editing on one (the one in the main MTW folder) and keep the other one as back up.

Gnome Editor can also edit "crusaders_build_prod13.txt" which is for buildings and "projectileStats.txt" which is for missiles/arty projectiles. Both are in the same place as "crusaders_unit_prod11.txt". You will need one copy of each file in the main MTW folder for the game to work.