How much of a pain is it to change a light fitting?
I have one of these and not only have two of the bulbs blown but I can't take one of them out to replace it as the glass cover has broken a bit too and won't come out. I doubt I can buy replacement parts.
Can I just buy any light fitting that takes my fancy and wire it up or do I need to figure out the volts and wattage and stuff? Am I going to need a drill?
You don't need to worry about power ratings unless you're trying to fit some industrial floodlights in your house.
Most lights will just screw onto the fitting that's already there. Certain larger lights might need their own special mounting plate fitted, which you might need a drill for.
>>2190 By turn off the power to the house I meant flip the main breaker because I don't know which circuits here are which yet and they're not properly labelled.
Even if they're labelled, never trust what's written on them unless you're bloody certain. It's all too common for dodgy electricians to spur off other mains circuits to make their life easier when installing a new light fitting, or to not bother properly relabelling after major work.
(Albeit in this case it sounds like OP has one of three lights still working so he could "test for dead" with that, at least. Personally I'd test with a probe just to be sure, and I'd certainly kill everything before sticking my hands anywhere near the fitting no matter how much of a rush I was in.)