rear bulkhead air vent replacement?

Hi, On the rear bulkhead there is a triangular shaped metal vent. Somehow this has gotten damaged (overheated?) and it is rough, similar to a grater. Clothing keeps getting snagged by it. I am trying to find out if I need to replace the whole drum (as my local repair shop told me - $300) or if it is possible to replace this vent screen. Is it possible to do myself? I’m somewhat handy, but not a pro. My inclination is to take the drum out and to try and hammer the vent screen so it is flat again. Any ideas? thanks!