Okay, step by step again.
1. Put all the 3.6.12 mediavps files in a folder called mediavps_3612
2. Go to your derelict directory.
3. Open up the mod.ini there.
4. Alter the secondarylist line to "secondarylist = mediavps_3612;"
5. Enjoy Derelict with the new mediavps.
6. READ INSTALL INSTRUCTIONS.
7. Read this thread
wolfen, unless you know EXACTLY what you are doing, DO NOT deviate from the official install instructions. They are there for a reason, that reason being that we (speaking as a member of both FSU and SCP here) cannot guarantee that everything will work correctly if you get creative. In my time working on the support board, I have seen more than enough issues caused by people who, like you, thought that they could ignore those instructions.