Eviction: Lawyer or Sheriff?

[Eric B.]

I recently heard some advice given that if you have squatters in your houses, you should send a sheriff, not a lawyer, to evict them.

My partner and I have two Illinois houses -- one in Abingdon and one in Freeport -- that we acquired via tax deed, that we have been informed have squatters. I want them out now. But I've never evicted anyone in my life (Welcome to the Real Estate business, Eric!!!). 

So what would you advise? Would you advise lawyer or sheriff?

Also I'd appreciate greatly anyone who can include in their advice exactly how to go about this. Is it as simple as making a phone call? Are there forms to fill out? How much should I expect this to cost me?

Thanks in advance for any helpful words!