Changing staff or two different types of staves on a single lead sheet

I'm working with the jazz lead sheet. The first four bars are a traditional piano staff of treble and bass for the piano intro. After the four bars I want just a single staff with slashes and chords. I can do the piano into and I am familiar with doing the slashes and adding chords, but I don't know how to switch from the piano staff to just a single staff for the chords and slashes.