Here is the link to the files:
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Take the terraign.def file, the Scenery_H.png file and the Default.par file and paste them into your scenery file (after making a backup of the original files).
With the slope soarer and glider files, unzip them and put them in your aircraft folder. (no need for backups- the original planes are still in there)
If your computer asks, replace the old files.
Gliders that I made:
Should I do more? I'll definitely make more planes, but how about the scenery?