99.9% of pythons are just as happy taking thawed frozen food as they are eating live stuff. In fact I have had, in the past when I didn't know any better, snakes refuse live food and then immediately latch onto a dead food offering. I'd be surprised if you have any trouble making the change work, if you do, it's just a matter of waiting them out - even if it takes 3 months before it eats a frozen thawed meal, and is not given anything else in the meantime, it won't do the animal any harm whatsoever. It is often the assumption that snakes need feeding every week that leads to people compromising and offering live prey. This is a big mistake.
Jamie