To disable ABS on the 650 (which is different from 1150-1200GS method)
2) not moving (so wheels aren't turning, feeding input to ABS sensor(s) and
3) gear in neutral
- hold down ABS button until light flashes one or two times, then release ABS switch. ABS light on console should flash slowly to let you know that ABS is disabled.
(doesn't matter that you have brakes engaged, in case you are doing this on an incline)
If you hold it down too long before releasing button (flashes 3 times) then it doesn't disable and you have to try again (let off switch as soon as it flashes first time - works for me every time).
If this doesn't work, then you may have a problem.
Chiang Mai, Thailand