Ring gear replace, Bobcat 753

We have a 753 Bobcat, think it's a late 90's machine. The flywheel ring gear and starter are going out, seems like some of the teeth on the ring gear have worn or broken off so we need to replace. How much of a job is this? does the engine have to come out? sorry for the questions, just haven't had much trouble with the machine. Thanks for any information/help, Patrick

Ring gear replace, Bobcat 753