My brother in law who is know longer with us rented out a house for me. Now I don't know where our copy of the lease is and they haven't paid rent in 2 months. What is the legal procedure of getting them out of my house?

As long as you can prove you own the house you don't need the lease, though it would help. Give them a pay or quit notice (the amount of time will depend on location a pertinent fact which you neglected to mention). If they don't pay in full by the deadline, you go to court for an eviction order.

Ah, the brother-in-law is no longer with OP. It took a while to figure out that clause.

I wouldn't even allege a lease in the court filing. It would only give the tenants a chance to raise a bogus issue. Instead, allege a month-to-month tenancy (as far as you know) and make the tenants prove the lease, if they deem it material. (if they think it makes any difference; it probably doesn't).

Since you are evicting for non payment, the presence of a lease doesn't matter. As AK said don't even mention. Simply point out they are 2 months behind in their rent.