The bad news it that you need to pull the flanges out of the wheel bearings to replace the studs. There is a very high chance that the wheel bearings will come apart and need to be replaced in the process. It would be counter productive not to give the flanges a proper measure at this point - if they're tapered you may as well bin and replace with either the standard part or the EP stronger part ... .both of which come with new studs fitted ... SO BEFORE YOU BUY NEW STUDS take the old flanges off and decide whether you need:
* Just new studs
* New studs and some new bearings.
* New studs, new flanges and some new bearings.
* New studs, new flanges, new bearings and some new uprights.
* To leave it all alone - S2 wheels are better
Cheers,
Robin