Posting your make, model and year will be helpful in case someone else has dealt with the same issue on the same coach.
Next.... Theater Seats typically don't recline. They only have the footrest extend. Only "recliners" do both.
The Theater Seats are usually two or three pieces. If you can open the foot rest of one of the seats, it should allow you to see how the seat is mounted so you can remove it. Removng one seat may give you access to the other seat to replace the cable or remove it so you can turn it upside down.
Many of the seats are modular. For example, the seat back may lift off after you find and release a locking mechanism. This video will give you an example of what I mean....
Then if you go to eBay or Amazon, you will find many universal replacement cable options. You will just need to measure the length of your cables and look at the style.