Blow off the pressure dome
A solid rocket can be stopped by blowing off the pressure dome with a linear charge. The sudden drop in chamber pressure will quench the combustion process. Unfortunately the plume that jets out from the pressure dome's opening will destroy the orbit vehicle.
The only viable escape system is an escape tower such as used on Mercury, Apollo and Soyuz. Some mechanism is required to rapidly pull the crew away from the launch vehicle's fireball after it destructs.
Gary