This part's Easy...The finished graft

The skin of the plants should be removed just a bit around the contact point so that when the soft tissue shrinks from dehydration after being cut, the harder skin won't push the union apart.
You don't have to remove a lot, just a milimeter or so.Then , lining up the vascular rings, place the two plants together.

Some use rubberbands to hold the two plants together, but I use nuts or washers tied to
 

string, or green plant-tie tape.That's all there is to it !.  Try not to get the union wet for two weeks.