i had a colt coral, may be similar. i got rid of mine that was about the size of my head. i used a zip tie at the base, and kept squeezing it every few days. it will pinch it in two, and the coral 'should' attach to it, and the cut will be clean/healed.
then whoever gets it could just glue down the zip tie. don't know if that will work for this coral though.
you'd still have some residue on the rock that will keep growing though.