Cutting and drilling into a Hangboard/gym hold

I'm getting a new Hangboard and realized that the best holds of my Detroit Rock Climbing V5.12 are all at the same area. I'm thinking of cutting out the 2 best holds and then screwing the new Hangboard on there. Because the V5.12 has holes going all the way through I won't need to cut through, and with the RP Forge I'm getting it should all fit together.

What should I use to cut? I was thinking a Dremel would do the job, it doesn't have to be perfect. I will probably sand down the cut afterwards

I already have some screw holes I will reuse but if I need to add new ones, what would be the best way to drill a countersunk hole into a resin hold?

I will post pictures. I think the resulting Frankenboard will be pretty awesome
Jon

Best would be to use a bandsaw but just about any type of saw will work. Just sand it with sandpaper. Drill with a regular drill and countersink. It's resin not rock.

A Dremel will take forever.

Any cheap hacksaw will work great on resin. I'm curious to see pics of this frankenboard when it's done.