it may be different in different states but here in okie you get a paper from your tag agent and fill out your info and what 6 choices you'd like... in order of preference in case one you want is already taken. then you mail it in and in about 3 months they'll mail it to you. you do send a check for 14 bucks (year of special plate) when you "order". then it'll have a sticker just like normal tags and you get that renewed when it expires.. which here is 13 bucks per year.
one side note... your laws may vary but in oklahoma you must keep the original plate in your car at all times. so i have mine stashed under the seat somewhere. not a big deal but its a huge fine like 200 bucks if you don't have it and they ask you for it.
just stop by the tag agent or DMV and ask'em. they don't bite... usually.
hope that helps. im sure its a bit different for states that use DMV for all the certification and all that bs instead of tag agents.