During our latest holidays unfortunately we dropped our d7000 and the internal flash broke (the plastic and the bulb are both cracked). Is this something I could replace myself? If so, where can I find the part?
I searched a little for you on Google, seems a few people have encountered this and they did replace the bulb on their own. I would caution that they had a different model but it's worth a look.
If you don't mind spending some extra cash you could possibly get an external flash unit (if you don't already have one) for your model. Pros of doing so would be getting more power from your flash, ETTL, swiveling flash head, possibility of off camera flash.
A little searching also revealed this could be a particularly dangerous endeavor. So the other option to consider would be also to bring it back to Nikon for servicing.