Your going to need a dial indicater with a magnetic base to reset the gear lash after you remove the ring gear and re-install it on your locker. This is a critical step, as it will determine the life of your gears! You can get a cheap one from Harbor Freight if you don't have access to one( borrow.) IMO, it's always better to buy the tool you need to do the job, rather than pay someone to do it. Then you end up with the tool, and the SKILLS and a better understanding of how things work.