Create mod map and change foliage in GE

[RTR52]

Need help creating my mod map. Seems there is no info out there as to how. Been able to create my mod map using GE. But it doesn't show up in game. There must be something I need to do to it??? Think many others are having the same problem, because I've only seen 2 modded default maps so far.

Also Having trouble with changing foliage textures on fields with GE. To many changes and not any tutorials as to how things work in FS17.

Very frustrated
Thanks so much for any help.