Remove tenants before? acquriing

[Abou C.]

If you acquire a 3-4 unit property and there are tenants there already, what is the best legal method you have done to remove them so you can pick your own tenants base on your screening methods. 

Reasons I ask:

1. I don't know what type of investor the last owner was or is:

2. I don't know what type of method he/she used to pick the tenants?

3. I Want control on who is living there and the metrics I use to screen them but the best return on my investment and reduce overturn and damage to property. 

Questions:

1. What method have you used?

2. And if if so what plans do you have in place to replace them ASAP?, should you be looking for tenants while trying to remove them?

3. Can I ask the owner before acquiring the property that i need them removed?.

4. What if they don't want to move since the lease will say move on x date?, can they fight it?.

P.S sorry for stupid questions, trying to cover my basis.