I replaced the belt tensioner and spring along with two of the drum roller assemblies. I purchased the OEM parts from AppliancePartsPros.com.
I used their videos as well as youtube videos for my specific model of dryer to figure out how to remove and replace the old parts.
The videos made the process so much easier than it would have been otherwise. The edges of many of the pieces are sharp, so make sure to wear gloves as needed.
I've only been using the dry for a few days since the repair, but so far so good.
This was my first time replacing the parts and the entire process (getting the correct tools, towels, etc, removing the old, and putting everything back together took about 3.5 hours. Many of the videos indicate about 2 hours, so I was slow.