You don't have to disconnect the brake lines, just remove the caliper.
You don't need a press, a big hammer works just fine.

Take the arm off the car. There are maybe 12 bolts max to get it totally undone. It's very easy to align again there is no reason not to take it off completely.

If you are lowered it's a great time to clock the bushing. Just draw up a straight line onto the trailing arm following the alignment of the inner part of the bush (when on the ground at normal ride height), then you can just install the new one at the same angle.

I don't think filling it up will work very well. The bushing is meant to move in some directions and resist others.