What year? On the 98-03 models it's under the front seat, just behind the back of the tank. You don't need to remove any bodywork, only the front seat pad. I'm assuming the later models are similar.
There are 2 bolts located at each rear corner of the seat pad. Take these out and the seat will lift off. What are you planning to do to your mates bike?
The bolts are 8mm I think and you have to lift the corners of the seat to find them. It took me ages and the user manual to work out how to get the seat off :T