Removing guitar

double click on the track in multitrack or click on edit > effects > stereo rendering (don't know the correct english translation) > center channel extractor > karaoke

this mutes the rythm guitars, drums and bass but doesn't delete the tracks so you can't crack the audio up into each instrument. so after you used this karaoke thing the lead guitars and the vocals at 100% volume and the rest at around 20%.