Place the new cooler over the cpu and align it with the four corners where the previous cooler was attached to.

Screw in the cooler, start at a corner and then move on to the corner diagonal from it, making an "X" shape as you screw them in.

It does not have to be tight, just as long as the cooler does not move, and both the cooler and CPU have proper contact with each other.

Plug in the power of the cooler in the same location of the previous cooler.