I have fragged goniopora and the methods I described for you avelepora are the same I would use on a goniopora, I would just like to mention that goniopora DONT handle fragging as well, the hardiest being red, then purple, then green are very susceptable to failure.
with goniopora I reccomend a wet cut instead of a dry cut if possible (wet tile saw filled with marine water etc.), after making the cut place the fresh cut pieces in a bucket of new marine water with a small powerhead pointed upward and heater to maintain even temperature for 1 hour so the coral can slime up and slough off. then return the frag and parent colony to as close to their original positions as possible to prevent light shock or other changes thay may cause the coral to expend energy acclimating to a new position rather than healing.
Note: gonipora are notoriously bad fraggers, I reccomend getting practiced on some hardier corals or a couple pieces of rock first. like setting up the tile saw and chopping up some rock about the same size so you get used to the way the saw cuts so you can make one clean cut without binding depending on the size of the colony you may need to remove the guard, be prepared for water to spray everywhere in line with the blade, (dont have your face looking straight down the blade you'll get a face full of water and coral goo)have a towel and safty glasses.be prepared to lose the entire colony, it does happen.
disclaimer: I am not responsible for anyones actions but my own, if you do use any of my reccomendations I will not be held responsible for failure/s. but your more than welcome to blame success on me.....