I've added thumbstuds to several knives, and in my opinion that particular knife does not look well-suited for a standard style stud or disc. Due to the full flat ground blade and the lack of flat/even area around the rear of the blade, there doesn't appear to be any good place to drill a hole for a stud. The only possibility, and I can't tell by looking at pics, is if there is enough flat area between the forward point of the triangular opening hole and the logo. There might be, I can't tell.
Installing a standard style stud requires using a carbide drill bit in a drill press to drill a hole through the blade for an aftermarket threaded stud.
As far as adding a disc, that's a much more complicated and difficult mod than adding a stud. In order to add a disc you would need to drill a hole down into the back of the blade, and then tap that hole for a screw. And between the thickness/thinness of the blade, and the fact that the blade is fully hardened steel, such a task would be EXTREMELY difficult, if not impossible for the average person.
An external screw-on stud like the one mentioned by BitingSarcasm might be your best bet.
