I have an Ibanez RG, and it's the only guitar I have with a floating bridge.

I learned a neat trick from a professional tech, and can now do my own setup.

As others have said, unlock the strings at the neck, then tune down about a 1/4 step. On the bridge, put the micro-tuners at about midway.

Now, the "trick" before you do the above. Use a thin stick, like a chopstick, and wrap cloth around it and place it under the bridge, which lifts it up (the cloth is to protect the body.) Now you unlock, and replace the strings one by one, then tune a 1/4 tone down. Lock the strings at the nut. Remove stick. The bridge drops down, bringing the strings roughly a 1/4 tone up. Fine tune with the micro-tuners.

I would suggest though, that you make sure the intonation on your axe be spot-on. If you have to pay for it, it will be worth it. I rarely even use the whammy bar, but was never able to find a fixed tail Ibanez I liked as much as the one I have. So I'm stuck with the floating bridge, but I love that it stays in tune so well.