How to reduce the detent on RAT 1?

[APB9785]

I recently bought the Red RAT 1 in S35VN, and it's nice, but the detent is WAY too strong. I cannot flick the knife open with either my thumb on the front stud, or middle finger on the back one. My RAT 2 handles both of these easily.

My question is how can I reduce the detent pressure so that I can properly flick the knife using the studs?

I've already tried bending the liner and filing around the detent hole, but neither seemed to have any effect.

 

[Blue Sky]

I personally would not bend the liner, especially to make it weaker. While it might help with the detent at some point, you will also affect the lock security. I would check the ball, maybe it could be seated a little deeper? And rather than file the detent hole, maybe a polish on the edge to eliminate any sharp edges? Flitz might work, albeit slowly. Slow might be good though.