Is it easy to attach the power on button on Iphone 4s?

My careless brother dropped my Iphone outside i dunno how the screen didn't crack but the power button got stuck, so i tried to get it loose again but it fell out altogether and there's a hole there but the button still works when you press it down, I ordered a new one off ebay but i have no clue how to attack it, do i need to take the phone apart or something? Is there any instructions online?

What would happen if I got this?

I'm trying to get an iPhone without the phone company putting me under a costly data plan. If an iPhone is factory unlocked does that mean anyone can use it as long as it's the same service provider (i.e an AT&T iPhone--factory unlocked--when I have AT&T)? Also will it just allow me to use whatever I already pay for as far as capabilities? For example, I have the 3G Service, and then the general texting and calling functions. Will that stay?

How to restore my backup on itunes?

I'm backing up my iPhone 4.so I can transfer the back up to my new iPhone 4S.
It asks me for a password but I don't remember ever making one. Please help,
I don't want to loose everything on my phone and start back from scratch!

Where can I buy a cheap iPhone 5?

I've been looking EVERYWHERE including amazon, eBay etc, but there's absolutely no places where I can get a rather more affordable price for an iPhone 5 other than '£500' which is totally silly money! The most amount I can budget on is £300! Can someone help?
:-)

How Can I, Easily, Learn, Japanese?

I Wanna Learn Japanese. What's An Easy Way, I Can Geach My Self, How To Just Speak, Phrases, And Replies? Not Rosetta Stone. Something, I Can, Easily, Use From My IPhone 4, With No Internet Requirments.