Product review (5 stars): Whirlpool Duet dryer repair hints
My dryer abruptly started making a loud screeching sound after several years of ownership. A quick search online based on the symptoms led me to believe it was likely bad roller bearings or slippage of the belt, both of which this kit could address at the same time.
I ordered this kit figuring it was worth a shot and a few hours of my time if it avoided me purchasing a new dryer (and the wife would probably want a new matching washer to boot :-) the kit arrived in a timely manner so I was able to get started with only a few days of laundry piled up.
I searched on YouTube and found a video made by an appliance parts company to walk through most of the steps. My dryer was slightly different as the front panel was not as easy to get off, but overall the video was really helpful in all the steps it provided, and the order to take apart/ put together.
I definitely recommend trying this approach rather than buying a new dryer. Overall it probably took me 3 hours to disassemble and reassemble everything. I wasn't really in any hurry, but took time to clean up all the lint and dust accumulated over the years at the same time.
While disassembling I also took pictures of things like wiring harnesses ( there are a few both above and below and I think one might be in the back if I recall) before disconnecting, and the way the  belt wrapped around the pulley underneath to minimize the problems of re-assembling things.
Really only a few other things to mention. Almost all the screws use a nut driver, so if you have one, it makes everything really easy. There seemed to be 3 types of machine screws used to assemble the dryer. Most are one type, so just make note of the few that are slightly different so that they go back in the right places. Also I missed one of the wiring harnesses that runs up the left front them at fell down under the roller drum, so I had to slightly disassemble to grab it and pull it back up. When you re- mount the drum on the rollers, ensure they seat properly (the video I found mentioned this too) and ensure the felt that seals the drum at the front and back makes a decent seal ( this also lets you know the drum is seated on the rollers correctly) and make sure the drum rotates freely as well.  As you assemble the dryer further and tighten all the nuts up, the felt seal further tightens so that your air is not leaking out, I wasn't sure my seal was good enough but it was fine after I tightened things up. When I re- fired up my repaired dryer, it was actually quieter than it had been in a while, less squeaks etc, so that was awesome.
Overall, it doesn't take a lot of skill, I consider myself if average mechanical ability, and had no problems by taking basic planning steps. I will post pictures, but don't let them scare you. This is fairly straight forward.  Good luck!