Its easy, if your mechainical,
I assume you have rear stand... put it on that. Then you have to loosen the axle (chain) adjusters on both sides, take off the cotter pin from the nut on the right side. Remove that nut, then tap the axle out with a hammer.
Than put it all back together with the tag mount in there.
You might have to disconnect the brake arm from the caliper, I dont remember.