Cant get the muffler pipe off

[Aircobra]

I must have watched a 1000 videos on this
from what i can tell, the standard process is to drop the muffler pipe to get to the water pipe olive
there are signs of a seal/o-ring at the top as you can see, but the pipe is not budging from the top
i have tried taking a propane torch to the top section to expand it, but worried i'm going to wrap and buckle the pipe

[Charles uk]

Remove the drive shaft tube from the crankcase first, then you'll have the bottom end of the exhaust tube loose, now wiggle it about!

[Aircobra]

had to upgrade my butane torch and heat the thing plenty but got it off

[Aircobra]

does anyone know the original paint type for these. posts talk about hammerite, but that cant be the original