I've heard two things about your model....that they are pre-wired for the gauge cluster, and that they aren't. If so, pretty much all you have to do is cut out a hole and slap that baby on there (hope you have steady hands).
If no wiring.....I would think it would be quite a process!!
Try checking out the search function, I know I have seen someone install one on their FJ and they did a write up about it.