HEY !!..... I am one of those guys.
You take a tire that will fit inside the your special ice race tire.. and you cut the sidewalls off and then you stick it inside the ice race tire... then you put the air in.. then you screw 4 of the 1 inch long special ice race screws into each knob... the screws penetrate the outer tire and go into the inner tire.
(this is done because the force is so great, that the regular knobs will rip right off otherwise)
Professionally done they cost $500 per pair.
The bad news? A $300 rear won't even last 8 hours.
Do them yourself and they cost $200 (not including your labor).
And traction?... LOTS of it... almost as good as these guys
(I couldn't find any ice race pics)