In this video i go over the basics of doing a timing belt on a 3.8 (2003-2006) montero engine. This procedure is roughly the same for the 3.5 gen 3s and also shares some similarities with the Gen 2 3.5. I hope this helps you tackle this job on your own!

Link to the timing belt kit
https://lusooverland.com/VP-LO-K-M3-TB/