Need your opinions on changing out vtc's
 

my buddy is looking at buying a 94 max out of our wholesale lot at work. It's super clean, leathers great, got 5 spd, roof, spoiler (its an se) but the vtc's are clacking bad. We talked to one of our techs who came from nissan and he explained the procedure. Has anyone ever done these before? whats really involved? Thanks

Eric