i use a large 2-jaw puller to pop the lower bj free from the knuckle. a pickle fork will also work, but unless you're replacing the bj (which you are) the pickle fork tears it up. sometimes you can get the bj free by hitting the knuckle where the bj goes through it with a ball-peen hammer, but i rarely seem to have success with the hammer method unless i have the help of a spring. after tensioning the 2-jaw puller fairly well, hit the knuckle with the hammer an the bj should pop right out (also works on outer tie-rod ends).
FYI, the bj press i rented was so wasted that i found i could not use it. so, i've also found that a 5 lb hammer (after removing the c-clip and supporting the the LCA with a floor jack) is an effective way of removing the old lower bj. i've used the hammer (with a suitably sized piece of pipe) to install the new lower bj by supporting the LCA, under the bj and pipe, with the floor jack and hitting the LCA on the outside edge. this caused zero damage to the LCA. this method would probably go easier if you leave the new lower bj in the freezer for a feee hours and heat the LCA with a torch, but it wasn't that hard to do without the doing this.