Montipora capricornis (plating) - just break off a piece and use superglue gel to attach it to a piece of rubble rock or another area of the reef
Montipora digita (branching) - break off a branch or use a pair of cutters to "snip" off a branch and use super glue gel to attach to a piece of rubble rock or another area of the reef
montipora...encrusting - a little harder but chip of a piece at least 1/2" square or larger and again glue to reef or rubble.
Good luck
SiF