I answered your question in my first sentence but I will try to explain it again. The 1st option is to trade Romo. Obviously, you want to get something for him if you can. This also saves about $5 million on the salary cap this year and $54 million in salary cap space over the next 3 years. If you can't find a trade partner for Romo then you cut him. We can't have a QB sitting on the bench making $14 million in salary this year, $19.5 million next year, and $20.5 million in 2019. Also, we need his salary cap hits off the books so we can start paying free agents like Zack Martin eventually. This dream that Romo will be content to ride the bench in Dallas behind Dak is just a dream. Romo has said that he wants to play. Dallas has stated that the job is Dak's. Romo asked Jerry and Garrett for a chance to compete for the starting job last year and was told no. Tony is the past and we are building for the present and future. The present and future will be easier to build with the cap space provided by trading him (1st option) or cutting him (2nd option).
Believe me, I would love it if Romo's contract was not like an albatross hanging around our salary cap necks and Romo was willing to be a backup. However, I don't believe that Romo will stay as a backup and the salary cap issue is not fixed by just lowering his salary/redoing his contract because there is so much prorated bonus money tied into it.