ok so on the rack???? Take the rack out, blank off the oil galleries, power wash it, pull the seal & have a good look, its not uncommon as a lot of road grime, leaking engine oil & stones are caught up in that area. Do the boots at the same time. Just count the number of full turns the tie rods are on so when you reassemble it the "toe in" is close as not to destroy a set of tyres on your way to have the alignment checked.
Its the seal from the steering box where the shaft goes out to the steering column. Apparently some guys do it with the rack on the car and undo the circlip then turn the wheel left to right a few times and the hydraulic pressure pops the seal out.
Not really relevant to a commodore . I changed the steering box seal on a disco on the weekend similar to that video bugger of a job its about the 3rd time I've done the same seal now it lasts about 6 months and leaks again, holding back the tide one might say. You have no hope of getting at the input shaft seal on a commodore rack with it in the car. Just get a change over rack on put that in? 9 out of ten National power steering are good blokes if it leaks they'll give you another one.