Hmmm... Well, I wonder if you can do it without the grafting... from what I've read the process can be difficult...
We've rooted a couple of things... Plumeria trees, Bougainvillea... not an expert but, I think you should try to root it first.
What has worked for us... Pick a young, green, fresh cutting... one where the branch has not hardened and there are only new and healthy leaves.
You may have to wait for the best time of year for this. It should probably be at least 8 - 12 inches long. Cut it as you would a bunch of roses... at a 45 degree angle, a clean cut. Dip the end in some Rooting hormone (available at any garden store) per the directions on the package. Then gently plant the cutting about 2 -3 inches deep in a pot of *sterile* peat moss that is slightly damp. Use a sturdy stake and very gently, but securely, affix the cutting to it.
Keep the growing medium watered only enough to keep it from being totally dry, but do not keep it wet. Place the pot out of direct sun, heat, or cold... such as in a shady covered porch/patio area. Only move the plant to sunlight after it has produced new young leaves.
In the rooting process, the old leaves will usually all die off. Thats one reason it was important to choose a young, lively branch. The cutting may not show signs of new leaves or life for several months (our Plumerias have often taken 3 + months). You will know if it did not root if you see visible rotting near the base of the cutting. Otherwise, Do NOT disturb the cutting! If you move it, and it had new, delicate roots forming, you may damage them and kill it. For us.. we have usually been about ready to give up and toss the whole thing out just before we see the new leaves
- Most of that is taken from advice written for rooting Plumeria.. it may not work for your tree