Guitar Strings Alignment
Guitar Tuning Problems- Help?
I’ve had an Ibanez GIO for about a year now, and only now I decided to change my strings. (yeah, yeah, I know) When I changed them by hand, the strings seemed fine at first until I realized that the G string could hardly bend, and it was nearly impossible to turn its tuning peg. When I finally got the guitar in tune, I could hardly use the tremolo bar, and the bridge was out of alignment. (the back of it was tilting up, as if I were pushing down on the tremolo bar) Someone help??
Since the bridge is tilting up (forwards) and the strings are very tight you have either changed to a much heavier set, or tuned the strings too high – possibly both. It can also be that you have put a heavier string on rather than a G-string (maybe swapped strings around). It shall never that hard to tune up to pitch.
Tune down first of all before something else gives and your neck starts to bow!
Your best bet is to take the guitar back to a store where someone can show you how to change strings and tune up properly.
If you’re using an electronic tuner, it is some times easy to be fooled by the readings. These tuners are meant for fine tuning a string that is close to pitch. You will need your ears, another instrument or some reference tone to get the guitar close to pitch before using an electronic tuner to fine tune the instrument.
You can also use an online tuner like the one here to give you a reference tone: http://www.howtotuneaguitar.org/
When you have found the string gauge you want to use, remember to make a note of what you have put on. If you use heavier or lighter strings then your vibrato unit will usually have to be adjusted to the new tension. And yes, a year is like way, way over bed time for a set of strings 
Basic Guitar Lesson