I've found that a couple drops of zoom oil or similar lubricant on the back of the screw before you try to loosen it works well. Someone else mentioned that a long time ago in another post and I tried it and it has worked every time. I've used the mini hack saw method before. Not fun.
It's best to buy the whole kit and replace all the moving parts. You don't know for sure the idler pulley is the problem until you take the dryer apart. There are 4 drum rollers inside also. Any one of those could be worn out.Part number: 4392067
Preventative maintenance is cheaper than a new dryer.
Notice the relocated control panel on the side wall. One of the luckiest days I've ever had. The complaint was the dryer would not start. The door switch was bad. The only component I could get to and test without doing carpentry work.
Thats one of those Bosch Ascenta dishwashers. There is a magnetic hall sensor in the top of the door that has to match up with the door latch. Could be out of allignment, check level of dishwasher. Could be loose or loose connection or could be faulty sensor or latch. The clean light coming on is a door latch fault code. Did you check the stored error codes?