How to update my jailbroken iphone 4s?

How do I update my jailbroken iphone 4s?
I'm running 5.1.1 jailbroken. I know, I haven't updated in way too long OTL
I want ios 7 when it comes out but I don't want to lose my apps, mesages, photos etc.

In short:
-I'm running 5.1.1 on an iPhone 4S
-I don't care about losing my jailbreak
-I want to update to ios 7 when it comes out.

What should I do?

Activating new IPhone on Verizon?

I have an iPhone 4S with Verizon and I recently cracked the screen. I want to buy the iPhone 5 from Apple but I was wondering if it would cost money to activate it and how I would activate it when I get it? I understand I would have to pay for the phone but I was just wondering if there were any other fees and if it was even possible to activate a different phone if I'm on a contract

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How to uninstall the iOS 7 software update on your 16 GB iPhone 4?

I have downloaded the new iOS 7 software update on my Mom's iPhone 4.It's still being downloaded as I type. How can I uninstall in and, get my Mom's regular iOS! Should I plug it into my computer and then, do what? Should I wait till it completely downloads then, do what!

App that I can save my videos to?

I have a lot of videos on my iPhone that are taking up my storage and it hasn't let my phone do a backup. Is there any kind of app that I can save all my videos to and still be able to save them to my phone in the future?