Patience and tough love.
Best way is to stop offering live and offer F/T until the snake takes it (this means your snake must have a good body weight)
Ideally thaw the prey at room temp next to the enclosure (this will entice your snake to eat), warm up with a hairdryer and offer. If not eaten try again the following week (do not offer live if the snake does not eat)
Just remember not all switch and some do but it takes a long time.