How to evolve rotom?

I have a couple rotoms and i cant find any of the items to evolve them i really wanna try to get them all can anyone help and tell me where the items to evolve are (really want the fire/ electric type)

You’ll find the appliances you have to interact with in the hidden workshop located at Kepler City.

They don’t evolve. The different typed rotoms are different forms.

But to answer your question, do what Decho said^