Window board

[chrisl]

I am in the process of removing and re-fitting a new window sil/board (inside the house). Problem is I cannot remove the old one!

I have tried inserting a chisel underneah but don't want to bash it too hard in case I weaken the window frame.

Any ideas? It's not really practical to saw it either.

Do I just use brute force!!!???

 

[AnonymousImport]

Are you replacing with wood? Or perhaps you can put UPVC over the top?
If not:
It is unlikely that the board will be fixed down in it's own right - but if it is try to lever it enough that the nail heads show through and you can pull them out.
Normally the board goes into the wall at each side - this is your problem - if you can cut in the middle (perhaps with a circlur saw (set on low depth!) or a chisel - this will give you a point to get a crow bar underneath and lever it out.