(works for Givi too, just substitute the Givi mount in place of the BMW mount)
Lift up seat and remove tail storage compartment cover. Remove anything in the storage compartment.
Remove right side body panel - you need to get at that edge of the seat.
Remove the seat. To remove it, you need to pull two cir-clips, or Jesus
clips (you'll know why when you lose your grip on it just as it comes off
and it goes shooting off into hyperspace -- Jesus Chr...!), one at the
hinge that locks the seat in the upright position, and the other in front
on the main hinge where the seat pivots, near the right side panel.
Unscrew the two hex head bolts that hold the main seat bracket in place and
slide the seat forward then up to remove.
Inside the tail storage compartment, on the bottom, you will find two
nuts that should have rubber protective caps on them. Pull the caps off.
Unscrew the nuts (10mm if memory serves). These hold the rear wheel fender
in place - the bracket they screw on to may fall out, no big deal if it
does, just set it aside for now.
Also inside the tail storage compartment, you will find two large plastic
headed bolts that hold the tail-light in place, unscrew these (they should
only be finger tight) while holding the tail-light with one hand so it
doesn't just fall free when the second bolt is removed. Unplug the wiring
harness so you can remove the tail piece from the frame. Since you're
there, I suggest spraying the wiring harness contacts with a electrical
contact cleaner (or Color TV Tuner cleaner), plug and unplug it a couple
times to work the cleaner in, then spray again to rinse any munge out of
the connectors. Some people suggest applying dielectric grease at this
point, I prefer a product called Rail Zip - available at hobby stores that
sell electric trains. It's used to clean the tracks and remove oxide from
them (thus the RAIL part of the name). Apply a little drop to each
connector and plug and unplug it a couple times to work it in - leave the
residue in place to protect the contacts, it should be easier to plug and
unplug the connector now. Remove the tail piece from the bike.
There are four hex head nuts and washers holding the top and bottom of
the tail piece housing together, remove them and seperate the upper and
lower pieces. You now have clear access to the inside of the tail
compartment!
You should see four posts inside the compartment with a detent in the
center of each, this is where you need to drill the holes to mount the
trunk rack. Approximate the exit hole location on the painted side of the
housing and put masking tape over the area to prevent the fiberglass from
splitting when the drill bit exits. Also, it is wise to place the painted
surface against a wood block to further protect the fiberglass from
splintering when the bit exits. Use a 6.3mm (1/4") drill bit and drill a
hole in each post through the center detent. Check that the rack mounting
bolts can pass through the holes without binding.
Remove masking tape. If you received a protective clear sheet, install
it. It's difficult to do and not have any air bubbles due to the compound
curves of the tail piece. I removed mine after putting it on because it
looked awful and I didn't see that it was really going to protect the paint.
Take a bolt, put a spring washer on, put a steel washer on next, insert
through tail piece, put rubber washer on and bolt into rack. Just thread
it on a couple turns to begin with so there is some free-play for the other
bolts to line-up with their respective holes. Repeat for the remaining
three bolts. I found that only three of my four would line up properly. I
ended up going back with a 3/8" bit to enlarge all the holes enough for the
bolts to line up properly.
Snug up the bolts (no torque value is given) and reassemble in the
reverse order. When putting the tail-light back in place, watch that the
wires are routed around the assembly so they do not get pinched when you
cinch down the two bolts that hold it in place. This is ESPECIALLY true if
you have run-n-lights or other light modification kit installed!
Total installation time is approximately 1 to 1.5 hours.
WARNING WARNING WARNING!!!
The topcases (trunks) have been known to spontaneously leap forth from the
mounting rack into deep outer space to hide on the 10th planet in our solar
system, which is yet to be discovered by OUR scientists, never to be seen
(or heard from) again. I HIGHLY suggest you protect your investment (I
believe a new topcase runs $350 US or so) by securing a coated steel
security cable to the mounting rack and the topcase - that way if it does
break free, it will hang from the back of the bike instead of skipping down
the highway.