Product review (5 stars): Worked for my 20+ year old Maytag dryer
I put in the Maytag dryer model and got this Whirlpool product.  Thanks to YouTube videos and the feedback left by others, I was able to get this on pretty well.  Our dryer is in a tight spot, so I did have my husband help me by reaching the belt from the front of the dryer while I was behind it making sure everything was on right.  Things others said that are true (in no specific order):

It is true that it's easier to see everything if you take the back off the dryer.  I don't think I could've done it from the front with my short arms.

Take the chance to vacuum out all the lint in there.  I was shocked by how much was in there and a potential fire hazard.

I took pictures of where everything was before I took it off so I could go back through my camera and see which plugs went where.

The belt DOES NOT go in the drum groove.  You'd think so, but it doesn't because there's not enough tension to turn the drum.

Search YouTube for your dryer model and 'belt replacement' and you'll find some great videos that'll show you how to take the dryer apart, put the belt on, and get it all back together.

In all, because of the small space and extra help, it probably took around an hour.  It's deeply satisfying to fix your own stuff and save money.  You can do it!