It's not easy. I pulled a p/s box from aBav many years ago, upside down in the sand and weeds...
You will need to raise and support the car securely. Suggest remove the box with pitman arm attached but taking all else off. Drain the p/s reservoir then disconnect the two hoses at the box letting the contents of the hoses run down your arm and into your shirt. Use a tie rod puller (if you have one) to disconnect the center track rod from the pitman arm. If no puller, use a pickle fork but know it will destroy the protective boot. Fun already, isn't it?
On top you have to disconnect the steering column from the box, at the column u-joint (more trouble, difficult to reach). Then unbolt the box from the mount and... "Out it comes" and the real fun begins.
However as noted above and in view of the trouble involved,make quite certain that it is incontrovertibly the steering box that is leaking. It's not unheard of that they can/will leak, but the trouble involved in R&R suggests you be sure where you're going before you start. The pitman arm seal could be leaking but I would want to be sure before I took out the box.
