There is a way to force him into a trade.
Surely Jerry has a significant influence over some/most of the the local media.
He could bring up old stories about Dak which do not paint him in the brightest light.
Further, he could be told that he will never play for the Cowboys again. He could either effectively end his career sitting on the sidelines for three and a half years being hated by the fanbase and his time as a Dallas Cowboy becoming a hugely negative experience and realistically no other team would touch him so this would effectively be it for him.
Or they could work on a trade together. The two teams he would probably like to be considered for would be Miami and the LA Rams based on Tua's concussion issues and whether Stafford retires at the end of the season. Flip side is will those teams really want to bring in Prescott!? Probably not is my thought.
In which case, the Colts, Giants, Seattle and Saints are all potential landing spots.
Whilst the front office is a huge issue for obvious reasons people need to get real and accept that Prescott is a busted flush and that his contract is kneecapping the team. The sooner they move on from him then the sooner the team can actually build to be a contender even if it takes several years.
The cap ramification will need to take a hit regardless.