When I was loading my Bosch washer this morning, I

When I was loading my Bosch washer this morning, I was careless and didn't see a towel still outside of the door. I closed the door (with the towel not completely in the washer) and started up the washer. I noticed that the washer was struggling and I stopped it. When I opened it back up, the rubber part that covers the entrance to the door was entangled with the towel and the metal ring around the rubber part was off as well. Through my own efforts I was able to put the rubber part back on, but I couldn't get the metal part around the rubber circle to stay. After 35 minutes I trying, I decided to run a load of wash (without anything in the way) and it worked fine.

How do I get the metal part back on or do I need to order a new one? How much would that cost? Could I install it myself?