Best approach would be to install a cheap set of adjustable levers. Typically around $50 and most give you 6 settings with a small adjustment lever so you can set your distance from grip to lever so it best fits your hands.
I don't think he is trying to alter the engagement of the clutch/the amount of freeplay, I think he wants the physical lever to be closer to the grip.Just give it more freeplay.
ie instead of 10mm std, give it 15mm at the ball of the lever.