hi matt get a round file and file out the hole till the studs fit in really snug then hammer them home , (the studs have grooves in them so they will bite into te side of the freshly filed hole , this stops them from twisting and becoming loose )then fit wheel and put a wheel nut on stud ! i did two on one of my hubs many moons ago i got them from vw heritage round about £20 for everything took about 2o mins job jobbered !!
the studs look like the ones 5th pic down 3rd bolt in
http://www.speedshack.co.uk/Wheelnuts.htm" onclick="window.open(this.href);return false;
hope this helps
regards
chris