materials.
6.35 mm drill bit
6.25 mm drill bit
1) pliers
2) 2pcs. dill bits ( 1 smaller than the cal. and the other the same as cal.)
3) vice or vicegrip
4) drill
clamp the pliers with a vice grip
make a punch on the desired location
drill the pliers using the small drill bit.
make sure that you do not drill through. once in a while open the pliers to see your progress.
again clamp the drilled pliers.
drill the opening with the big drill bit with a depth of 1mm or more.