is it easy to replace the rear abs module? Do I have to take apart the whole dash to get at it? How much is the part? It's for a 99 f-150 rear abs only.

 

Are you talking about the speed sensor on the rear axle? If so, this is very easy to replace...one bolt and the electrical connector and you are in business...it is located on the top of the rear differential. I replaced mine (99 F150) in about 10min.