He can't do anything. That's kind of the point of what he's saying. He'd happily sacrifice something very important but it wouldn't change anything.Ok. But what is Morrissey freeing Marr from? And what could Morrissey possibly do to free Marr from ‘it’?
The 'it' is whatever's confining him. Holding his creative spirit back. The music industry, contractual obligations, personal restraints, pick one. It doesn't matter what exactly 'it' is.
It's about being free and able to create great art again.