89 disc coversion to 94???

My brother has an 89 mustang LX 2.3L notch back, we went to the scrap yard and found a 94 with 4-wheel disc brakes. he said the rear axle should bolt right up, BUT going from drums to discs? will we have to do anything with the brake lines and will the master and brake boost have to be changed or could we use the stock LX system?