Just take a good new clean straight razor and cut it at the base of the coral . Take some super glue and glue it on then take a rubber band and band it on . For good measure place it in a small dish or soap dish (depending on size ) and let it in there for a couple weeks it should naturally attach ,,then move it from the dish to where you want it . .. If you want and have an area to where you want it in your tank cut it and wedge it in between rocks do not place it in direct flow but gentle flow and in a couple weeks time it should have attached . One thing I have found that after cutting you may get another.And if you dip it in Iodine ( 1 part iodine to 10 parts water I think) it will help stay off infection ..