The Notice

Kim just asked me for a favour. I'm asked to type out a notice for the person who's renting her apartment. A notice to ask them to MOVE out because she's going to sell that house of hers. How am i supposed to do that??

Dear 'whoever',
I would like to.....(notify? What? What to write??) You have till early April to move out. (Sounds weird man...)

Ok, i really have no idea how to do this. Anybody who can help write one for me?