Noob help!

[cxavierc21]

I am on my third xv6700 now (I am clumsy) and my usual go-to-guy went to college. I just give him my phone and he gives me some great OS. Since he is not here I figured I'd just do it my self. After about 20 mins of looking at this site I have a bad feeling I will mess up my phone if I do this my self. I am hoping that one of you guys can walk me through what seems to have been a 'kitchen' upgrade.
I only know you have to download it and put your phone in bootloader mode and that is it; I don't even know how to put it in boot loader mode.

More detail the better, thanks so much in advance!