125-200cc help please with cr125 exhaust

hi guys,not been on for a while but i really need some tips for getting my end can apart so i can repack it,ive an 04 cr125 with a standard silencer,i cant get bloody thing to shift,i warmed it up with hairdryer,while taping a bar round edge,all that did was make end of the cans body look shit!wd 40 didnt help,is there some magic way to make it come out??
also i want to drop the needle but cant work out how to get the cable and spring out of the slide,does spring twist out or just pull out?please help me as im going to Silverstone gp track this weekend for the first enduro loop and mx track, 4x4 test area so id like to get it done.
thanks steve

For the silencer, I run a razor blade in the gap between the pipe and silencer body, hold the pipe and tap on the mounting tab with a plastic hammer.
for the needle theres a plastic retainer you have to pull up out of the way to get the cable out. sometimes it comes up with the spring but usually you have
to hold the spring back and pick it out with tweezers or a small hook tool.