You dont work something out, you cant renegotiate your CBA before the amendable date without the approval of the membership. If the company violates the CBA you file a grievance, that is how it is handled.
Its quite clear you have zero idea on how the RLA, Collective Bargaining nor how the Grievance Procedures work.
You prove your ignorance.
I will give a few examples:
At US the IAM for M&R had CBA language that if any other unionized group gets a 401k match, that the IAM M&R will get it also. They matched the FAs and denied to match the IAM, we filed a grievance, went to arbitration and the IAM and its CBA language prevailed, man that was a nice check into my 401k as long as anyone else who from M&R participated in the 401k.
At US we filed a grievance in regards to the HMO and what US was charging, we filed a grievance and it went to arbitration. The IAM and its CBA prevailed, man everyone was happy with their nice refund checks we all got!
At US we filed a grievance that the company was outsourcing meal carts to be fixed, we filed a grievance and won, the cart shop employees got a nice check for the CBA being violated.
Shall I continue?