How to cut existing mointed cornice?

[dustycooks73]

I’ve added a false wall to my carport to turn it into a rumpus room I want to add cornice to finish the job, I  am having difficulty  cutting the existing cornice to the correct angle as I can’t use a saw

[Jason]

Hi @dustycooks73,

You might like to add some photos to your post so members can see what you are working with and be in a better position to provide advice on next steps.

Thanks,

Jason