My dryer - which is about 20 years old - was starting to make some rubbing/scraping sounds from the drum area.

This was pretty much as easy as most other folks had described on this site.
1. Removed the two screws at the front bottom that are holding on the fromt panel, and then lift up and remove the panel.
2. Disconnect the door-open-safety-switch, remembering which color of wire goes on which connection.
3. Remove the four screws (two on each side) on the front bracket that supports the drum and tthat contains the front glides.
4. Remove support bracket and lint trap, letting the drum rest gently on the stuff underneath.
5. Remove the screws holding the lint trap to the support bracket. (My model had five screws.) Remove lint trap from support bracket.
6. Drill out the two pop rivets on each of the two glides, noting the orientation of the teflon pad and mounting strip.
7. Secure - and here is where I had a little problem - new glides in place with pop rivets. (I hadn't use a rivet gun in a while, so I messed up the first pop rivet and had to go to the hardware store to get a replacement. I didn't hold the pop rivet in all the way while I was accuating the gun!)
8. Reverse the process for assembly, and you are all done.

It's simple.