If your AC has an EL or EH chassis prefix, then it was fitted with an ENV axle from new. Some earlier ACs were later converted to the ENV axle. To confirm what axle you have, an ENV axle will have the part number H106-1 embossed at the bottom of the differential flange, and "ENV LONDON" at the top. The dip-stick may also have ENV written on it.
The original type are leather with a thin metal casing that is hard not to damage during removal. I found that the easiest approach was to budge it slightly outwards, using a hooked impliment such as a cheap chain wrench (for oil-filter removal). Failing that, a 90 degree lever tapped with a mallet. Once it has moved slightly, a 90 degree lever can be inserted between the back of the seal and the ridge in the axle casing, then twist the lever and prise the seal out.
After the outer oil seals are fitted into the bearing housings, the outer-races of the bearings can be pressed in. My old bearings had evidence of damage due to installation, and these are difficult to get in. I pressed mine partly in using a "Workmate" type bench, and then used a large vice, with wood to protect the parts from damage from the vice jaws. I also kept measuring how far it was going in, to make sure it was going in square. Once the race gets below the surface of the housing, you can use the old race to help press it in home. Use the side of the old race with the radiused edge, as you don't want to get that stuck in the housing!