Its a doddle to change the subframes.The whole job should'nt take more than an hour max.The exhaust and most of the wiring stays where it is and there is only a few bolts to undo. First you remove the seat unit by removing the two bolts underneath and the two on the side of the frame.Gently pull the seat unit up at the back to release it from its rubber mounting.The tank is bolted to the seat with a 17mm bolt.You should be able to get at it by propping the rear of the tank up.I use a bit of 4x2.The tank can stay where it is and the seat can be removed. Unclip the wiring connector on the side of the subframe and remove the exhaust can fixing bolts.(4x5mm Allens?,cant remember) Remove the 4 subframe bolts and it should come away from the frame.Fit the bip stuff in reverse procedure. The seat pads are all the same,so all you need is the bip seat unit and subframe.The pillion seat is locked to the subframe,so you may need a lock key,not sure if the finger under the cable trick works on these bikes. Marksduc748 who posts on this board was breaking a 749 and may have some bits you need. As mentioned above,you may need to change the shock as the Ohlins is reputed to be on the soft side,and check if the lightweight wheels are up to the job.
i reckon the wheels should be ok, i only weigh 12.5st and if i'm gonna take a honey on the back she will have to observe the strict supermodel weight limit of no more than 7.5st:P