Might be a stupid question but do you buy them already studded? They look like an off the shelf unit so I’m assuming so.
Not a stupid question at all. I had the same questions when I first looked into it.
You can get them pre-studded, but the drawback is that they are very expensive (I'm no baller) and you don't get to choose the kind of stud (length, material and brand) to use, as well as customizing the stud pattern, depending on if you want more grip on the edges, less in the centre, more rear grip vs more front grip, etc.
All of those choices depends on the kind of riding you're going to do, terrain, skill level, etc.
With pre-studded tires, every single lug is studded - which is not necessarily a good thing. I ended up opting for more rear grip over front, so less studs in the front.
IIRC, I put in around 300 studs for each rear, and 200 studs for each front. For four tires, it took about 4 hours total over 3 days sitting in front of the TV drilling each stud in one at a time:
My back was killing me after I was done.