How should I put the power button for iPhone 4?

Hello,

I followed the guide on iPhone 4 Power & Lock Button Replacement and finally got up to the last step. But im confuse after taking out the iphone 4 power lock button, how do i install it? like i tried top side and bottom side of the iphone 4 lock/power button, they both fit through but the back side doesn't, so i know its the front just not knowing its the up side or top side, and i see that it has a clip in the back where it is movable, i was wondering which side do i have that at?

But yeah i installed a brand new iphone 4 power button today by the guide above, and i just install it by either top or bottom side, i forgot and not sure which is accruate cos i can't tell. But yeah now my iphone 4 power button got worst, instead of it being stuck or really hard to press, right now its so slim, soft able to press but it just doesn't have any effect.