The easiest way to do it is to remove the spring.............the guide rod forward bushing can then be replaced in the process.

If the spring remains in place, the forward bolt on the guide rod cannot be removed. In this case, you must thread the mount to the rod with the rod in place.

If you followed Roy's approach and removed the entire bearing bracket, you might prefer to start the threads into the rod before you secure the bracket to the frame. In this scenario, the LCA won't need to be pulled foward by an ungodly amount in order to start the threads (thereby alleviating the massive twisting moment on the LCA bushing).

Note that I have not attempted this approach because I did the job with the spring removed.

Good luck.