Few important things on the situation in general first it is a 2.5 years old animal which means he knows how to eat and therefore assist feeding or force feeding is not an option. He can also go on for a long amount of time (a year is not unheard of) without any issue aside from being frustrating for you the owner.
Going of feed can have several causes, seasonal changes, breeding mood, fasting to catch up when offer to much food (remember that they are being overfed in captivity).
The key to help an animal resume feeding after a long strike are, making sure that the animal as an optimum setup double check everything, sometimes downsizing the enclosure will help the animal resume feeding. Most importantly it's really about patience.
Now as far as switching prey type it's never really a good option unless you change to another commonly fed prey item such as mice and even than you must be prepared to feed the other prey type permanently same if you go from F/T to live so if it's not what you wish to do patience will be what need to be demonstrated.