Removing spark screens

[Bermie]

Ok, call me a doof, but how do I get the spark arrestor screen out of my 021 and MS250 mufflers??
I take off the nuts on the front but how the @(#* do you get to the screen behind the flap of metal that appears to be totally immovable?

 

[Lakeside53]

The metal cover is probably rusted on. Whack it.

 

[Bermie]

Thanks Lake, 044 sent me some pics, worked on them today, all done and dusted, easy when you know how!
Took the opportunity to give them a good clean with the compressor, happy saws.