Dave, cant tell from the pics but if its 1mm or 2mm you can use a decent pair of tin snips. If its good quality without too much resin they will cut it like scissors do paper. Try in a corner first to see how it cuts.

If it splinters then use a very thin wheel on a grinder and finish with coarse grit paper and a block.

If it cuts fine then finish the edges with some 1000 grit wet and dry.

Carbon once you get used to it is actually quite easy to work with.

Be careful with splinters too.