Had the same problem. The packing is binding against the exhaust. Spray WD40 or whatever lube you have onto the baffles. Yes it's messy.dickman said:
Put the screws into the welded nut from the inside. Hook a coat hangar
or similar wire around the screw and yank. Once you get it a ways out
use heavy duty pliers to twist and pull.
Have patience. Be careful I remeber falling on my ass when the wire slipped.
When you repack, tape the material tightly. You may even want to try the
baffles without the packing.
Good luck.