Lease renewals and tenant additions

[Danny Ritter]

I have a 3 bedroom in which I am writing up a renewal for year number 2, but the current tenants are removing one tenant, and adding a new one. Do I need to draw up a brand new lease, or can I have the new tenant sign the renewal if it stipulates that they are being added and the other tenant removed? So the new tenant is now party to the original lease which she did not actually sign.