Just for clarity: Without the crystal, and with the jumper set to take the clock signal from the motherboard, the CPU should still work on the Blizzard. Fitting the crystal and using it instead will make the CPU (and FPU) run at the crystal's frequency instead. As Paul pointed out, be very careful of fitting it around the correct way. The FPU should only fit one way, but the oscillator can fit 4 ways, and only one is right. It should just plug into the socket though, you won't need to solder it.
Edit: The orientation should be marked on the board, you can't assume it's just upright. There will be one corner on the crystal that's different to the other 3 - sometimes it has a dot printed on the case, sometimes a different shape of the metal container on that corner. This corner should be marked on the board some way or another. If it's not, I would say that the marked corner goes with the notched corner of the socket (pin 1) which can be seen to the lower left of the socket in the photo further up in this thread. Hope that makes sense!
Also, just for pedantics, the crystal oscillator is actually a small circuit, containing the crystal itself and some other components needed to make a clean, square-wave clock signal.