Doing a rebuild on a 79' Suzuki GS1000L with some changes into a Cafe Racer. I was restoring the Exhaust pipes and muffler and ran into an issue. The mufflers (inside is very rusty & dirty) are welded to the pipes which are not quite as dirty. I've been able to remove the rust and scrub the pipes but cant find a way to get into the muffler to clean. Any ideas? Thank you in advance for any assistance!