Please help.

Alright, so I customized a theme (Customizr), and I was completely ready to “go live” with the site. All I wanted/needed to do was make it so my http://www.siteexample.com/wp site was http://www.siteexample.com. So, I researched and literally found about 9 options. I tried one, updating the functions.php file (via FTP) within my theme with a couple of (update option) strings of code to change the site url and home of my site. That didn’t work. My site looks like it lost all stylistic features of the theme, it looks broken. So, instinctively, I simply removed what I added, and reuploaded the file to take its place. It’s still broken. Then, I tried another option, to “hard code” the wp-config.php file of my site. That completely locked me out. So, now I’m back to the broken site (it’s there, it’s simply completely without all of the stylistic feature of the theme I was working in). Please, someone, I have FTP access, 1) how do simply get back to where I started (I can’t even log in to my back end now), and 2) simply change my site url without the apocalypse reigning down on all my hard work and excitement. Please help.