New member located in northern New Jersey. Lease advise

[Derek H.]

I have two tenants that have lived in my property for more than the 2 years I've owned it. They've yet to officially sign my leases and being as though I'm a bit on the relaxed side, I haven't made a big deal or when I have I eventually let it go. My question is, Am I able to establish a lease at this point, and if so, when and how should I go about doing so? Any advice is appreciated. Thanks in advance.