You need to take the engine out and take off the flywheel to get to the ignition. Here's what it looks like:
The round thing with the yellow wire coming out of it is the condenser. Make sure your new condenser has the little bit of oily felt stuck to it.
You might be able to wire up an external condenser without removing the stock one, but I'm not sure if that would work. You would hook it up to the low voltage wire on the coil (the part with the little rubber boot on the left) and make sure the condenser's case is grounded.