Pre '06 you could just take a hole-saw and cut the disk from the rear of the muffler, an just pull the rear baffle out. after '06 it gets a bit more involved.
For detailed V* info here:
http://forums.delphiforums.com/yamaha1100
And especially here:
V*Star 1100 KB (FAQ) - T-O-C
The knowledge base covers just about everything you could ask!