@Heidy Fernandez I agree with @Joe Splitrock to an extent. It comes down to your area and how the courts tends to rule. Here they dont want anyone "on the streets". I had an eviction takes over a year to happen because the judge gave them 2 extentions and each time I had to start the serving process over and mean while they were not paying. They had'nt paid for 6 months and the judge gave them another chance and cost me another 5 months. All the while zero payments. So do what works for you in your area. When I do cash for keys, me and my guy take back possession the minute I pay and all locks are changed. So they have to break back in (never happened in 7 years). Also in the OP's case they have no lease as its expired and once they give the keys and go back its now trespassing and if they break in its breaking and entering. Again in 7 years investing (never had this happen). Homeless people, yes, but no previous tenants have ever come back and broken in.
And when Joe said you dont have to finish, that was also correct. When I mention letter Im reffering to the first step in the process. I simply use my legal service for the letter and it rarely goes past that as it comes from an attorney and its very aggressively written.