Creating your first engine - PatPL/Generic-Engines GitHub Wiki
(This guide shows Generic Engines v0.3.3, let me know if it gets too outdated)
This tutorial will guide you through the process of creating your first engine and exporting it to KSP.
Click the first, + button to add new engine to the list. The engine should appear below.
Double click a field to open edit mode. Commit your change by clicking Enter, ok clicking off the field. Don't forget to mark the engine as 'Active' (First checkbox field). Inactive engines will be excluded while exporting. (They will still be saved to the engine list). More about .enl & .cfg files
After you're done with your engines, you can save the list to engine list file (3rd or 4th button). To export the engines press the last, sixth button. If everything went right, .cfg file should appear in specified location. As of v0.3.2 Generic Engines will generate a PlumeScaleFixer.dll file. It has to be copied to GameData as well. Otherwise plume on engines may be misaligned.
Just move every file generated by GE while exporting to GameData folder
(Default location is $My Documents$/Generic Engines/Exports, but can be changed in settings as of v0.1)
Move the engine to your KSP's GameData folder. You can create your own folder in GameData to store the .cfg files too.
Now launch KSP and check if the engine is there.
That's it! Have fun!