I watched videos on the disassembly of my dryer model, and got the model number hiding on the upper dryer door jamb. After calling AppliancePartsPros.com for help, then ordered parts with the help of APP. It took almost a full day to disassemble the dryer I have, as it is a little more complicated than some models, and I went very slowly on purpose to not lose screws, or break plastic parts.
Getting the wiring harness apart was the hardest thing to do, as the screwdriver shown in the video was way too big to get under the plastic edge and release the tab, so I had to use a very small screwdriver for this, and still, it was a fight. The plastic housing cracked in the process, but only on one side, so it did not prevent proper reassembly.
When I got the dryer drum out, it was obvious what the problem was obvious, as the Idler pulley assembly had frozen and would not turn, which had caused the belt to burn a bit. So I was glad I followed the recommendations of the APP rep, and got the entire assembly, since just the roller would not have been able to go on the frozen old hardware.
I had to watch the placement of the belt pulley which looks so simple online about 10 times to be sure I got it right since the view shown in the video is the reverse angle from the view I had when doing the repair.
I was careful when vacuuming out the dryer cabinet not to let static build-up, up since that can damage the electronic control board- I kept touching the motor housing during the vacuuming to discharge the static and didn't use a brush on my vac hose.
The dryer works much better now, and I will keep it for a long time, since I can repair or replace most any part of it, now that I have had it apart and put it back together. Parts cost about 150.00, and included the idler pulley assembly, 4 drum support rollers, and a new belt.