Editing parking

First of all, I am a total novice so please go easy on me.
I am using FSX SE.
I have the P3D v1.4 SDK installed.

All I want to do is change the parking sizes at FAPE from small to medium.
Have no clue. Please help - the manual is GREEK to me!!

I assume this is the default FAPE airport?

1. Start ADE.
2. Menu - File/Open Stock Airport.
3. Type in FAPE.
4. Click on FAPE in the box.
4. Click Open.
5. Click on one of the green circles - these are the parking spots. It will turn orange.
6. Press enter - the Properties box will open.
7. Click the arrow to the right of Type entry. A drop down box will open.
8. Choose GATE MEDIUM from the list.
9. Click OK.
10. Menu - File/Save Airport. Change folder location if needed - I use ADE/FSX/Projects.
11. Click Save.
12. Menu - File./Compile Airport. Change folder location if needed (must be an active FSX scenery folder). I use FSX/Addon Scenery/scenery (the default).
13. Click Compile.
14. Start FS and check out your edited airport.

Hope this helps,