Some of my studs are crossthreaded from the last mechanic who replaced my tires and wasn't paying attention to his impact wrench. The problem is, there is no space to get the new studs in, and I had to cut the old ones out. Is there any way to replace them without removing the whole tire assembly and potentially messing up the seal and ball bearings inside? (Brakes and everything else necessary to normally replace studs has already been removed. The problem is that there isn't enough space between the opening and the more complicated parts of the tire assembly, and there isn't a groove like there usually is for replacing studs.)
Is this on the front or the back? Also, did you try taking the brake rotor off of the hub?
In either case (front or back), you should be able to remove the caliper, brake pads, and rotor off of the hub. When you get down this deep, there should be plenty of room to get the studs out and replace them.
IF you cannot get the studs out, you'll need to take the hub assembly off from the steering knuckle. To do that, there is the bit nut which is used to keep the drive axle in place on the front (left image). Then there are three bolts which hold it onto the steering knuckle (right image). Be careful when pulling the hub out as you can damage the wheel bearing and would need to replace the hub.