Co-signers for rental leases - New Jersey

[Greg Torian]

Hi everyone,  I have a tenant already in one side of a duplex I'm about to close on in Medford. He currently has a co - signer for the lease in place now. I've seen copies of past rent checks from the current landlord and am comfortable with him staying. 

  My question is how do you place a co- signer on the lease agreement,  and any suggestions on finding a lease agreement on line?

  Thanks,

Greg T.