wrap a towel around a flat head screwdriver and pry up slowly.. it does have double side tape. pry up on the leg slowly and it'll come out.. don't scratch the paint.
what do you mean the nsx r spoiler does not come with studs? who did you buy it from?
even the cheap one from seibon comes pre-studs so all u have to do is reuse your old nuts.
you should NOT have to studs the new spoiler.. .. i would NOT remove the factory studs from the oem spoiler.. leave that alone.
if u need studs then go to lowes, home depot, etc and get some threaded rod about 1in long.. get some locktite thread lock, some nuts and then you're set.. i'm assuming the new nsx r spoiler been threaded from wherever u bought it from.