Thanks for posting this ... I just upgraded to Elite Membership ... knew I would eventually, but this post saved me enough time and grief, I was glad to offer my support right now.
Just got my 98 Sport a month ago. This weekend, I was changing over to some alloy rims and tires I got. In the distant past, some butt monkey with an air wrench screwed all the wheels it waaaaaay too tight ... at least 150 ft-pounds. I am very surprised that my brake rotors seem OK. I could barely turn the lug nuts using a big breaker bar.
My right rear axle ended up looking just like the first pic posted by Fredness... two snapped studs. I live in Florida ... no road salt. In 30 years of wrenching on cars, I have never broken one ...much less done it while
removing a lug ... slowly
I had to walk away from "Sporty" for a while ...
Calmed down ... found this post. What a time-saver! I was sure that I was going to be popping the axle open and taking the axle shaft to a shop to have studs pressed in. Instead, I had two new studs in there in about an hour, and wasn't rushing to do it.
I wanted to add a couple of tips ...
Got the new studs and lug nuts from NAPA ... less than $2 each and they are definitely grade 8 hardware. The local Ford dealer did not have any in stock ... (probably ran out ....

)
Not sure about the markings on the original studs ... "CH" and no bars ... does that mean "case hardened" or "China"?
Bring a lug nut with you to the store ... they list two different varieties.
I don't have a stud installer ... got good results by this ...
Got the stud in place by sneaking it in there from the bottom and using a long skinny needlenose pliers to basically line it up. Could not get it directly in there, but jacked up the other rear tire (limited slip rear) and had my wife turn that just a bit, the side I was working on followed, and the stud popped into place.
Lined up the splines, and put a 1/2" stack of Grade 8 washers on the stud. Grade 8s fit tighter to the bolt and help assure that it is going into place straighter. They also won't gall like softer ones. Then, I turned the lug nug around backwards so that the flat face was on the washers, lubed it all up with PB Blaster, and started turning it all into place, using a 3/4" open end wrench.
Once the splines are about 1/2 way home, it starts getting a bit tighter, and you need more leverage. I took the washers off and scrounged an old spindle nut that I had here. It is probably a 3/4" thread and 1/2" thick. The conical end of the lug nut fit into it well, so I turned the lug around and used a breaker bar on it. Again, make sure everything is oiled... have a small puddle in the lug nut. Turning the lug around also makes use of some other thread area on the stud, hopefully not over-using the same ones you started with. This got the stud home. You can watch your progress and right as the stud gets there, it all snugged up and really did not want to turn any more.
Take your time ... if the lug nut starts feeling warm, let it cool down. Be slow and deliberate about this, and you will get-er-done.
Again ... thanks for starting this post!
I was really thinking this was going to be much more of a job than it ended up being.