Grinder, Hacksaw, Paint, Drill and Bits, File, Solder Gun
and Connectors, Wide Assortment of Wrenches
As you can see by the difficulty meter above, this was the hardest mod I've ever had to
make.    It is also one of the most visually rewarding.   So, if you can bring yourself to
permanently modify your Monster's frame then you're ready to go!
Now for the hard part-  take out your saw and get ready to cut your
pristine frame!   :(   The point right behind the flat plate is a good
spot.   I am using
turn lenses that were left over from my MH900e
signal swap, and they fit perfectly over the frame tubes.   The
lenses were from this kit; I don't know where to get them
individually but if I find a place I will let you know.   I am sure
similar ones are out there.   Try
Signal Dynamics for a product that
will work equally well.  It took me about 6 tries to do this and after
the first cut I honestly was sick to my stomach and had to take a
break.   The second cut is a little easier!
Once the frame is cut (forgot to mention that the line you cut it at
will intersect with the lock housing plate).   It may look a little
wierd with the plate cut part way off, but that's where this step
comes in.   Take your grinder and round down the currently vertical
plate.   Then take the grinder and cut a slot between the tube and
where it is welded to the plate (this step is only necessary if you are
using lenses that slip over the frame like I did).  
Now you can take your file and clean up all the sharp edges and
generally inspect your work.   Test fit the signals and make sure
the one on the right makes a nice fit in the slot you cut.    You can
also see I already mounted the light back and installed a zip tie pull
handle for the seat latch until I can rig up the license lock cable to
the front side.
Then take your paint marker or similar and paint any bare metal.   
I found a nice gold marker to match the frame (sort of).   You
don't want rust in there.
Now onto the signals.  Remove everything you can get at.   Then,
bundle it all up in its new home under the seat (I have already
removed my under seat tray so it was easier for me ;)  and zip tie it
all clean, leaving enough room to wire the new signals in.  The
license plate light is now delete because the brake light illuminates
it just fine with the plate right under it.
Use your drill to make a small hole on the insde of the frame tube
to run your signal wires through.  Make it large enough so that the
wires slide in easy and don't rub.   Then take a round file and clean
the edge so they don't rub through and short on the frame.
You can then drill the hole through the signal and the frame and
tap the hole for a small machine screw.   You may notice the
aluminum trim on the signal lens-   I just bent that around the lens
so it gave it a nice finished look.
Here's a close-up of the lock housing trimmed down, with the slot
cut in the plate and the signal mounted up in there.  
Here's a back shot of the plate mounting brackets I made.   It's
just some aluminum strap bent at an angle outwards and down so
that it can use the existing bolts/holes of the stop light and still line
up flat with the back of the plate.    
And here's the finished product:
Simple enough with the right tools, and the procedure can be modified to suit your needs/taste.   Good luck!
S.p.A., all other content on this website is copyright 2006, Monster Man Productions.

First step is to take off the seat, remove the tail light mounting
nuts, then get the four black plastic tray bolts off and this what you
see.   The entire section from around the tail lock back will be gone.  
 It doesn't support anything except the license plate, so no strength
lost.   The tail lock cable is easy to remove-   just loosen the nuts on
the left side and take it off the mount, then the cable has enough
slack to take it off.   Then it slides out the left side, through the
right, and you can take the lock mechanism off and its gone.
Here's the pic of the socket I used-   this came out of a 73-87
Chevy/GMC pickup front sidemarker/signal housing.   Cost:  free
at the junkyard (no I didn't pocket it!).   You can also get a similar
socket for about $4 at the auto parts store.  It needs to be trimmed
to fit snug inside the frame tube, but once in it won't vibrate.   
Stick the wires through before soldering the bullet connectors (that
will plug into your stock signal wiring) on.   otherwise you can get
the bullets through the small hole you drilled in the frame.  Then
you can shove it up in the frame, plug it in and put in your bulb.   I
used a #192, a single filament stop/signal bulb and it is quite bright.