You can try taking the nozzle off and cleaning it out with a torch. This will involve taking the thermistor off, so you will need some Kapton to tape it back on. If you bought a roll to use on the bed you could cut a strip of that. I recommend keeping a roll of 1/4" kapton around, it comes in handy a lot.
Heat the extruder up until the plastic is able to come out. Shut off the power and unplug the connectors for the heater and thermistor, and pull off (without using bare fingers) the black insulating sleeves from the nozzle. Very carefully try to unscrew the nozzle, taking care not to crush the thermistor. You can cut the kapton and take the thermistor off now to make it easier, but you don't want to give the plastic too much time to freeze up again. You might need to do something to secure the black insulator barrel if it keeps spinning.
If the whole barrel unscrewed from the insulator, then that's fine, you can clean that out too. Carefully unscrew the heat core from the barrel, which should be easy. If you need to unscrew the nozzle from the barrel, don't hold the barrel directly with pliers because you could crush the threads. Run two nuts down the barrel and tighten them against each other. Hold the nuts with the pliers while you unscrew the nozzle using a socket wrench. You might need to warm it with the torch to soften the plastic inside.
Warm the nozzle and barrel enough to soften the plastic just enough that you can pull it out and it will stretch and pull more filament along with it. Then go outside and start torching the nozzle and barrel (separately) in earnest. When you start to see smoke and flames, you know the stuff is starting to burn out. That's why you are outside. Keep a small cup of alcohol handy and drop them in to cool off after they have been flaming a bit so you don't get the brass too hot.
Once the nozzle is cleaned out you can try shining a flashlight through it onto a piece of paper, as if you were viewing an eclipse. I'm not sure how useful it is, but you can see if the edge of the opening is clear. You might also see a couple lines that seem like a blockage, but are actually the filaments in the bulb.
Check out this video for a demonstration of the torching-
http://youtu.be/6bTfl35zlHE
When you put everything back together, make sure the heater core is screwed down as finger tight as you can get it against the nozzle. When you tape the thermistor back on the nozzle, make sure it is covered completely with as little air surrounding it as possible.