uShop and functions
 

I tried installing uShop and I was doing what it told me in the readme file... replacing codes and whatnot.. but I wasnt doing something right and when I removed all the changes and restored it to default, it made my forum a bit weird.. meaning that it wont let me change the username colors for usergroups anymore... But I know that I removed and replaced all the codes back to normal... If I delete functions.php and reupload it and replace it, will it mess up my forum? Like will all the posts and settings stuff be lost? All I want to do is replace the functions.php that I tinkered with; with the original one that came in the unzipped file.... I just want to know if it will mess up the forum in any way if I do....