Here is what you need:
Rear sight punch:http://czcustom.com/czbrasssightpunch.aspx
Front sight roll pin punch:http://czcustom.com/czpunch.aspx
Front Sight Drill:http://czcustom.com/CZ_Front_Sight_Drill.aspx
You can buy them from CZ Custom, or at a local tool retailer like northern tool. Just make sure you have the right dimensions.
Fitting The Front Sight:
Remove the roll pin using the appropriate punch. Tap the old front sight out (towards the muzzle) using an appropriate soft hammer or soft block
Replace the new front sight into the dovetail and tap it toward the back of the gun until it seats in the rear of the dovetail cut. Make sure it goes all the way to the back of the dovetail.
Using the front sight drill: Drill through the roll pin hole. (IMPORTANT) Drill from the left side of the gun to the right side, Drills cut clockwise and drilling from this direction will not cause the front sight to walk out as the drill starts to cut.
Replace the front sight pin.
Fitting The Rear Sight: Remove the slide from the frame and place it in a vice. Using the rear sight punch, carefully tap out the rear sight. Replace the rear sight with the new one, and gently tap it in using the rear sight punch until it is aligned. (There is an alignment mark in the center of the rear sight, and the center of the top rail of the slide. Tap in until aligned.)
All done and you have new sights!
Here is a video on how to do the front sights:
Here is one for the rear sight: