An irrevocable trust (QTIP), in which the grantor died, named his wife as income beneficiary and she just passed. His son is the trustee and remainder beneficiary. The son wants to use the existing trust document versus drafting a new one under his name since all provisions, except the following two, are already stated. 1) The son has a special power of appointment exercisable among a class consisting of his spouse, lineal descendants, and spouses of his lineal descendants. If he foregoes this special power of appointment, the trust for his issue only will apply, but he wants his spouse to be his beneficiary and then his issues to follow, so can he simply draft a codicil instructing this? 2) Can the same codicil be used to name the son’s spouse as successor trustee? The trust says that the successor trustee shall be the trustee nominated in writing by the son.