Small Engines (Lawn Mowers, etc.): go karts, drive sprocket, rear wheels

Question
how difficult is it to change the drive sprocket on the drive axle on a ACE Patriot go kart with a 6.5 hp tecumseh engine?

Answer
not to bad.  remove rear wheels,  remove axle assembly.  the drive sprocket is either bolted to a plate, keyed to the shaft or has a roll pin in it.  Look for set screws and loosen.  Or look for a round hole that goes all the way through.  Drive out the pin if this is it.  To help more I need model and serial