Hi:

I'm going to replace a large basement window installed in a concrete block foundation. At the bottom of the window, there is a 3.5" x 6" cement cap, beveled in both directions. It is too narrow at the top to be of use in the new installation, and I want to chisel it out and replace it with 2 x 6 pressure treated lumber. Is it likely that the cap will chisel off easily, or am I more likely to damage the block to which it is affixed?

Thanks in advance for any advice.