Front Sight Drill. Number 47 Drill, for making the hole in the new front sight. Fitting: Remove the roll pin using the appropriate punch http://czcustom.com/czpunch.aspx 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 back. Using the correct drill, http://czcustom.com/CZ_Front_Sight_Drill.aspx Drill through the roll pin hole (IMPORTANT) Drill from the left side of the gun to the right side, Drill 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, new pins are available http://czcustom.com/czfrontsightpin.aspx