Immediately put the bottles in the bottom shelf of the refrigerator overnight (or similar). Then, the next day while they are still totally cold, carefully lift each cap and try to let pressure out. If they spooze all over the place when you try this then you have two choices. Either keep them permanently in the icebox and always serve then cold as hell with lots of extra towels on hand, OR open them over a big bucket in such a way that you capture the wine as it sprays out and then once you've put all the cider into the bucket you can take another shot at re-bottling and continue on.
Regarding pasteurizing ... if you do manage to get to the point of pasteurizing with bottles that may be over-pressurized, for pete's sake, use a LID on your pasteurization pot and wear eye protection and heavy gloves. As you introduce each bottle to the pot, keep the lid in the other hand, low over the pot; and use it as a shield in case anything explodes.