Well if you WANT to do it, and not take it to a tech then I can give you step by step instructions...count yourself lucky, cause changing strings on an EBMM non-floyd equipped guitar is like no other experience. First off you're going to need some tools handy, a Phillips screw driver, a tuner, small wire cutters and one of those smaller Phillips, for the rear plate.
Step 1: Since we know ahead of time that the springs will no doubt tighten I would go ahead and loosen them a bit. So go ahead and turn(loosen) both claw screws until you see the bridge raise slightly at the back. So you're bridge should be at a slight downward angle, sloping down towards the neck.
Step 2: Starting with the high E string, remove the old string by de-tuning first, unlocking the tuner, then finally pulling out the string. Then turn your tuner untill the hole aligns perfectly to the nut slot of the high E or to the direction of the neck. String the new high E string through the bridge block, out through the bridge, through the nut slot and in through the eye of the tuner. Pull somewhat tight and bend the string back away from the center of the neck. Tighten the locking tuner and then cut the excess string. Tune to pitch. Strings should always wrap from the inside or centre of the neck out: Check the pic
Repeat this for the remainder strings. Then once you replace all of the strings stretch and tune the strings repeatedly. You can use a cloth to stretch the strings gently.
Step Next: Now that you have replaced all of the strings, stretched and tuned them to pitch, you may notice that the ffloating Petrucci bridge may not be level. This can now be corrected by a process of adjusting the claw screws and tuning the guitar to pitch at virtually the same time. I suggest you do what I have instructed so far then if the angle is off, we can then adjust it. Keep in mind that the guitar may need to be set up and/or intonated...but we can look at this later!
