Its not too bad a job, but takes a little time.
You will have to remove the swivel/wheel bearing assembly from the rest of the axle to get the new one on, so you will probably have to unbolt the brake calipers and braket with the brake lines through it.
WD40 everything as the bolts will probably be well rusted, but take car not to get it on the brake pads of course.
When i put new seals on mine they needed a liberal quantity of silicone gasket sealent round the outside of the seal, the replacement seals were to a good fit. Probably metric seals in and imperial housing.
You shouldn't need any specialist tools.
For the 6/7 bolts holding the ends onto the axle casing, you will need a good ring/combination spanner, a socket won't fit :x . To get enough leverage either put to combination spanners together or cut one in half and slide a tube over it to increase the length.
