There's a counterweight to the exhaust ( erm ... not nearly so heavy) situated at the left footpeg.
I'm sure instructions on how to remove it are on this site but I can't remember how the article was described.
I'll have a hunt and if I can't find it again I'll revisit what I did and let you know - prob be the weekend though.
I fitted a Beowulf end can and am very happy with it.
Rgds
Chay