While GSX Hoolie’s method would work, it is perhaps a little…direct! Many bikes have rivets that hold in an end plate on the end of the exhaust silencer (or can). However I don’t think this is the case with the Vulcan (it’s illogical Captain), as if I remember correctly it has slash cut pipes. I thjink if you want a better sound after market pipes might be your best option.
PS. Don’t save for a HD, go for a 2.3 liter Triumph!!