Sometimes you are the outgoing pastor, sometimes you are the new guy. Once you have been the new preacher, you evermore hope the old pastor gets it right. As the Lord said when commanding Israel to be kind to foreigners around them, "For you were strangers in Egypt" (Leviticus 19:34). You've been there; you know how it feels.
There are several schools of thought on how the outgoing pastor can ease the transition of the incoming minister.
One says the pastor should train his lay leadership so well, with them doing their jobs and keeping their eyes on Jesus, that when the pastor moves on, the church transitions seamlessly to the new minister's leadership.
A second says the outgoing pastor should work alongside the incoming preacher for weeks, months, up to a year, before leaving. However, few strong (incoming) pastors want to serve as backup to anyone for very long. Most of us have sufficient confidence in our Lord and our abilities to want the former pastor gone so we can get started.