Here are pics of my 2005 636 with free GP set up. I had a 2003 636 but the front sprocket cover was in the way but on the 2005 the front cover is recessed so the shift rod will clear. You will have to space (red arrow) the pivot point of the shifter with 2 small washers from your local hardware store. unbolt pivot point and reuse single washer already on bike then add 2 washers then retighten bolt, you should be able to feel bolt on back side of bracket when tight, normally this bolt protrudes through bracket about 1 to 2 millimeters stock, it should be flush with bracket after mod.You will have to flip the piece connected to the gearbox 180 degrees and pull out as far and still have the bolt that runs through it tighten.It will have about 1 to 2 millimeters play when bolt is loose this is normal. You will only have about 1 millimeter between shift rod and frame but it works and best of all its FREE.
be careful when u do the gp shift, make sure u locktite that bolt that is pictured above with the red arrow, if u dont it will back out on u on the highway like me and my bike had to sit like 1.5 weeks while the parts came in the mail. learn from my mistake