Legal Question in Landlord & Tenant Law in California

If by "let them go," you mean end their tenancy and evict them, the answer is "you can't," unless you plan to take the home off the rental market permanently. San Francisco has strict "just cause" eviction rules. The only alternative is the "Ellis Act" which permits taking a property off the rental market entirely and prevents you or any subsequent owner from renting it out again for many years. And even then it is a lengthy process and will require relocation payments. The odds of you following all the rules and jumping through all the hoops to properly and legally do this without hiring an attorney on at least a consulting basis are about zero.