redrilling plates for 90 deg hitchpins

[jimialeggio5 at comcast.net]

Any experience redrilling plates for vertical hitchpins
particularly in the bass bridge section of the plate?

The existing holes are drilled at an angle, and I'm sure
a redrill will try to follow the old hole and make a mess
of things.

In a chat with Del, the word was to shear the pin off at the plate,
spot the new hole center at the back edge of the old hole, 
and drill 1/2 diameter through the old pin and 1/2 diameter 
behind the old pin.

Any other opinions on how to pull this off? Just looking for as much
experience/opinions as possible on this before jumping.

This is a small chickering quartergrand redesign, so there is 
not much room behind the old pins to just move the pin
way back (or even forward on a few pins).

What materials and diameters have others used for the new pins.

Jim I