switching from Nexus 5 to Nexus 6?

I have a Nexus 5 purchased from the Google Play store on a T-Mobile prepaid plan. I would like purchase a Nexus 6 from the Google Play store and use it instead of the Nexus 5.

What do I need to do? Move the SIM card from the Nexus 5 to the Nexus 6? Anything else?

Should I reset the Nexus 5 to factory settings before or after I remove the SIM card? Thanks.

Bill