A previous post about topworking explained that my four year old pears are small enough to graft all in one go.  However, I've also read that it can be tough for a tree of any size to suddenly lose all of its branches, so some orchardists leave a few in place to shade the scionwood a bit so it's not exposed to blazing sun while trying to get established.  As a result, I decided to cut into the main trunk just above the first pair of limbs.

The other factor to consider when preparing your tree to be grafted onto is ensuring you make a very clean cut.  The success of a graft depends on the cambium, which is the thin layer of living tissue just under the bark.  So, if you cut a tree and it tears half the bark off one side in the process, your grafts are going to be less successful.

I worked around this potential problem by cutting about halfway through the tree, then coming around to the other side and cutting through the bark there.  When I finished my cut, the top fell off the tree without damaging the bark at all.  (By the way, these sharp little saws are awesome for making precise cuts like this.)

Timber!

The final step in preparing the tree to be grafted onto is to trim any irregularities from the wood.  One of my cuts came out perfect, and the other needed just a tad of whittling with my sharp knife.  Now the tree was ready to accept scionwood and to be turned into a new variety.