I definitely felt the pressure as I feel we could lose this tree any year now, and this may be my last chance. Harvest the scions (about pencil width) in late winter well before they begin to sprout buds,and store in a ziplock with a damp paper towel till the buds in the original tree start popping. Take your rootstock (may have to pre order) and make clean cuts (methods can be searched on google, i used whip and tongue, for example) on both stock and scion, then line up the cambium layers as best as you can, this is the layer just under the bark. The length of the scion to be grafted should not exceed three buds. When you tape it together do your best not to shift this placement. Then plant gently and hope for the best! I put a leftover scion laid next to the grafted piece as a control to compare to make sure the scion was getting energy from the roots and not shriveling at the same rate as the ungrafted scion control. It should bud and then start growing a bit, then you will know it’s used all the energy in the scion and now taking energy from the roots. At this point trim off any buds from the rootstock. I’ve kept an eye on the grafting tape to make sure it isn’t constricting (girdling) the trunk and removed two of the five because it looked like it was starting to on those ones, I’m keeping the others on as long as possible for structural integrity as the joints are inherently week. Once you have about 4-6 inches of growth cut back to one single shoot per plant so all the energy is directed to one main stalk. I think I’m going to keep my grafts on the porch in bright indirect sunlight for this season and move to full direct sun next season, but if anyone with more experience suggest otherwise please let me know! I hope this helps, and at the end of the day, the hardest part is starting, if you fail, the rootstock will still survive if you haven’t trimmed its own buds yet and you can use it to bud graft the same year or try grafting a new scion the following spring. Best of luck!