Solution
I went from windows to a macbook and what I did was if u have a external hard drive, depending on how much data u have, just go to your itunes library on your windows comupter and copy and paste it all onto the external then take it to the mac and open itunes and click add file from fold and drag that itunes library to your new one. It'll convert everything and will bring all your ringtones, music, movies, and purchases, it'll bring everything you had. Takes time... but that's the how I did and I have everything.
Hope that helps.