I'm afraid I'm not familiar with the Nike Carbon skates, but the good news is that skate wheels come in standardized sizes and are thus interchangeable, so if the skates are comfortable you can just replace the wheels. Look on the frame, or the box if you still have it, to see the maximum size wheel that is compatible with the frame. Or just get the same size - 76mm, since you know they'll fit. FYI, though, 76mm is now considered a small, and thus slower, wheel by today's standards. 80mm is much more common.
But if you're just getting started with inline skating, you might find the smaller wheels are actually easier to learn on - they give you a slightly lower center of gravity and you may prefer slower speeds at the beginning, especially until you master the art of using that heel brake to slow down and stop!
If you have a local skate shop, please try them first. It's important that we support our local skate shops or we'll lose this valuable resource to our skating communities. If there isn't a bricks and mortar skate retailer that sells replacement wheels in your area, try http://www.inlinewarehouse.com
or one of the many other "inline online" retailers!
(Last tip - if there's a Play It Again Sports or similar used sporting goods store near you, they sometimes carry barely-used inline skates dirt cheap. Sometimes you can pick up a pair of these for less than the cost of a set of new wheels!)