Here are the easy steps to activating SXAD HOBBY in FSX and FSX Steam Edition:
1) After installing KHOU into FSX or FSX SE, run the simulator.
2) On the main screen press “Settings”
3) Then open up the “Scenery Library”
4) Now click “Add Area”
5) The main FSX directory will open, scroll down to the folder SXAD, Open that and the SXAD HOBBY folder
6) Now click “OK” and then again click anywhere in the empty space below the other folders as shown below
7) SXAD HOBBY should now be listed on the scenery library priority list, you can now press “OK”, and after waiting for it to load the new scenery, it will be ready for use!