There is no drain plug on the Breva 1100 fuel tank.
Removal is not difficult, but is made much easier if tank is nearly empty (that's about a 40 lb tank when it's full). Most difficult part is getting the "quck connect" fuel line connector under the tank to disconnect. That part is best done with a helper holding up the tank while you work underneath. Once you have done it and see how it works, it is much easier, however the first time can be difficult.
Read this. It describes the procedure for fuel tank removal, including how to disconnect the balky fuel connector.http://forum.guzzitech.com/forum/topic.html?f=189&t=1503
Good luck. Let me know if you need any help. By the way, for what purpose are you removing the tank? One thing you might want to do while you've got the tank off is replace the plastic fuel filter with a metal one. If you need help doing that, I've got lots of photos from when I did mine.
Photos (double-click on them to enlarge):
View of bottom of fuel tank
Flange on bottom of tank where fuel pump resides. Quick connect fuel line coupling is red/white part.
Close-up of disconnected fuel line flange.