On Sat, 24 Mar 2012 08:27:25 +0000, Alt Beer wrote:

The glass in an external wooden window frame is cracked and needs
replacing. The putty at the bottom of the frame is cracking and easy to
remove but the putty at the top and sides is rock solid. What is the
best way to remove hard set putty without damaging the wooden frame?

I used a straightedge with a knife to create a groove along the seam,
then a putty knife placed in the groove and gently tapped with a hammer
worked well to lift the old putty. Then take the glass out and clean up
the frame edges before priming.

cheers

Jules