It is possible, but somewhat technical. The graphics portion of the CD+G has to be split-off as a separate file in a proprietary format. Then the audio portion is compressed, the files can be transferred, the audio file decompressed, and the augio and graphics recombine. For starters, not every CD burner can read the graphics portion of the CD+G. The traders are on a MIRC channel, and they expect you to bring stuff to trade. However the oldest of them have 250+ discs of material, and all the latest stuff gets traded. They have also got lawyers bugging them, and I am not sure if they are up and running at the moment

step 1
find out whether your burner is compatible

step 2
get software that can copy cd+g format

step 3
get software that can split and combine cd+g files

step 4
find Mirc channel (the channel uses a version with special scripts)

step 5
learn to upload and download songs