Any way to switch from iphone 4 to iphone 4s?

So i have an iphone 4 (my contract ends in a few months) and my father had an iphone 4s maybe two years back (he has iphone 6 now) and i really wanted ios7 but i forgot to download it so i'm stuck with ios6 and it makes everything so difficult (i can't download most apps, its way too outdated, etc). My father on the other hand (his old 4s) is ios7 however he has a different apple id and just different account in general. I understand i can wait a few months so i can get a new phone but i really want this ios7 now… What is the easiest way to basically transfer all my information (i can redownload apps and music i'm mostly concerned about having my own apple id so i can manage my phone easily) ANY Help WILL BE APPRECIATED Thank you!

Added (1). UPDATE: I HAVE AN IPHONE 4S IOS6 WHEREAS HIS IS IPHONE 4S IOS7

Take your iPhone 4 that you are currently using, and plug it into a computer with iTunes installed on it. A page in iTunes with the phone will pop up. You want to back up the iPhone but make sure it isn't backing up to iCloud, you want it to back up to this computer. After that process is done, unplug the phone and plug in the 4S you want to switch to. A very similar page will pop up. Now this process will delete everything on the iPhone 4S. Click restore iPhone and wait for it to complete. You may be asked for his Apple ID and Password. Once that's completed, it will ask you how you want to set up the new phone. You want to chose the "from backup" option. This will move everything from the iPhone 4 onto the iPhone 4S. Now depending on you mobile carrier this process will be different. If you use a GSM carrier like AT&T or T-Mobile, you will just need to take the SIM card out from the old phone and put it into the new one. If you use a CDMA carrier like Verizon or Sprint, you might be better off just going into the store and having them activate it for you. They shouldn't charge you anything for this. Hope that helps.