Tricks to win over a stubborn live-only eater:

First, feed live, but with the cage/drawer open, and you present. If you can get your snake used to that, then move on to the next step.
Offer a stunned rodent on forceps. If that is accepted...then on to the next step.
Offer a freshly pre-killed rodent on forceps.
Stick to that routine for several weeks, and make sure the snake is well used to it.
Heat an FT rodent until it is hot to the touch (not burning, but hot). Rub the rodent in soiled bedding from live rodents--they usually pee in one corner. This is gross, but get that FT rodent completely scented with the pee from the live ones.
Offer this to your snake, promptly, while it is still hot.

9 times out of 10 (or better), this will be accepted. There's always that one snake once in a while that will give you a really dirty look, and turn away, but most will be fooled. Once they've taken FT this way a few times, you can offer it unscented, and they'll scarf it right down.