Extract new_dark.zip and contrib.zip contents into main install folder (this overwrites shock2.exe).
Optional: Read through cam_ext.cfg to see if you want to tweak anything. I recommend "d3d_disp_scaled_2d_overlay 640 480", as it makes the UI larger and easier to read from the MFD. Any of those changes you want to make go into cam.cfg file. (edit: Still monkeying around with the rez...it only seems to like 640 480?)
Extremely impressed. Works flawlessly on Win7 64, so far...there goes my weekend.