Again thanks for all the tips and experiences guys.
Spigot - I did buy your idea for a while there and put one stud in the freezer to do a test run with. My cover was blown when the missus opened the freezer (surprise, surprise) and asked "You do know there is a bolt sitting in the freezer don't you???????"
But I didn't end up going the freezer approach!
The replacement studs were just short enough to place in the hubs without taking them apart, and even though I was prepared to go the whole hog and take the hubs out after Gdub and a good mate of mine strongly suggested not to take the easy way out, the lil bad backyard mechanic in me said "comeon, just one stud... just try it.. it won't hurt"...
Next thing the washers were out, i oiled up the knurl, placed the washers on the loose stud, tightened it up with a nut placed on backwards, braced the hub with a straight bar and carefully pulled them through with nothing more than a long socket piece and a 530mm breaker bar!
The knurl on the new front studs was 0.5mm bigger in diameter than the old ones, so they pulled through very tightly but didn't slip one bit.
The knurl on the new rear studs was only 0.1mm bigger but still pulled in with good resistance and didn't slip a bit either. Thank fark, cos I didn't want to source another sliding hammer to pull out the rear axles!
BTW, I found out the other day that a sliding hammer is called a '****er' in German ('Wichser'). Pragmatic as always, zee ol' Germans!