My question involves landlord-tenant law in the State of: California

I'm currently in a Month-to-Month contract with 2 other roommates. I have just provided them with a 30 day notice that I am planning on moving out. I am actively looking for someone to take my place, but should that fail, I'm planning on leaving anyways. I was informed by my landlord that both roommates must amend the lease and sign me off or I am still liable. But they are refusing to (read: holding me hostage) unless I find a replacement.

There is a section in my lease that states that we can terminate the lease in it's entirety as long as we provide a 30 day notice.

There is another section that states: If there is more than one Resident under this Agreement, each Resident is jointly and severally liable for all rental obligations. Violation of this Agreement by any Resident or Resident's Related Parties is deemed a violation by all Residents. Requests and notices from us to any Resident will constitute notice to all Residents and Occupants. Any notices from, consents by or actions taken by any any Resident are deemed to be a notice from, consent by, or action of all Residents. All demonstrations, inspections and explanations made by us to one of the Residents will be binding on all Residents as if made to each of them. Any Resident or Occupant who has permanently moved out according to another Resident may, at our option and discretion, no longer be entitled to occupancy of or keys to the Residence. However, the termination of that person's right of occupancy will not release that person from any and all obligations under this Agreement or any renewal, unless we specifically agree otherwise in writing.

Question 1: Is the landlord allowed to/required to have other tenants essentially "sign me out" of my lease?

Question 2: If I give the other roommates the option to either A. Remove me from the lease and absorb my portion of the rent. or B. to terminate the lease completely can they turn them both down and force me to stay liable?

What other options do you recommend?