In California, if a tenant moves out without 30-day notice and puts a friend in the unit, WHOM do you evict?

Renter signed a contract agreement. Then moved out without giving a 30 Day notice to landlord. The original tenant “moved” his friend into the unit. No additional deposit was ever paid (so original deposit was not returned to the original tenant). The landlord was not in agreement for a “long-term” new renter, but agreed to let the new person stay for a short term time period.

From the onset, the rent was one month late, then after 5 months, the (substitute/friend) renter stopped paying any rent and refuses to leave.

It has now been over 3 months without any payment from either the original renter or the substitute. Whom should be served the eviction papers? Should BOTH the original renter and the substitute both be listed on the Eviction forms?

Thanks in advance for your time and assistance.