1. Solution the First: buy a program like iPartition. Make sure it is a version that still appropriate to the OS you have.
2. Solution the Second: obtain a cloning program like either SuperDuper!--costs $--or CarbonCopyCloner--which I believe is free. You should do this anyways.
A. Clone Your Internal Hard Drive: to an external. Again, you should do this regularly if you use this computer a lot and wish to preserve the data.
B. Boot with Disk Utility: either from your Installation Disk or you can boot from your clone and use the program in its Utilities folder.
C. Erase and Reformat the Internal Hard Drive
D. Create Your Partitions: this is done with Disk Utility.
E. Clone Your Clone: to the partition you want with your cloning program whilst booted to it.
MacBookPro 2.8 GHz Intel Core i7, 16 Gig RAM, 10.8.3--"Okay . . . I will try Mountain Lion!"
Fear Me! FEAR ME!
His secrets are not sold cheaply.
It is perilous to waste his time.