You said the front subframe. Is it the front front-subframe, which the front motor mount attaches to, or the rear front-subframe, which the rear motor mount attaches to. The rear is harder, and requires taking apart everything attached to it, even the powersteering rack. The front one should be a lot easier. Just take off everything attached to it, but in the new one and reverse your steps. I had to replace the rear front-subframe on my cb7.