How to remove tenants when acquiring a new property

[Lukas Schmidt]

Hi, I'm a beginner investor in Wisconsin. When you buy a new property that has tenants currently living in it, how do you remove them legally? 

Specifically I am looking at buying a duplex and moving into half with an FHA home loan, with a property that is occupied on both sides.

A few of my questions are: 

Is the lease the tenant has with the previous owner still valid? Does it bind them to the property? 

If they don't want to move out do I have to go through eviction or is there a different notice/letter I need to serve them? 

How soon can I have them out of the property or at least start the process? Ideally I'd like to move in as soon as I own it but I understand if I have to wait 30 days or whatever legal length of time is necessary to allow the tenants to leave. 

Thanks for any help on this I appreciate it!