The hardest part of changing/replacing engines is getting the electric clutch/pullys from the old engine, you may need a pully puller. Most of the time the pullys come off with no problem, screw driver or wrecking bar usually brings them off. The rest is just a matter of disconnecting and reinstalling gas line, wires and t-cable. Don't forget to tighten all bolts and put oil in the new engine before trying to start it. Some people do forget to do this. Good luck.