Stock handlebar adjustment

Has anyone tried to rake their bars farther foreword? I loosened the clamps and the bars wont rotate.. I am assuming their are some locking pins. Has anyone removed the pins so the bars can go forward? I am 6'4" and long arms....would like to move them up.. I am afraid if i grind out the pins the clamps will not be strong enough to hold the bars firmly in place.
Anyone tried this?????
Bueller..