how or where can replace the top back cover of my iPhone wihout having to send it away?
Here are all the tutorials you should need...
http://www.anandtech.com/printarticle.aspx?i=3026http://www.ifixit.com/Guide/iPhonehttp://thinksecret.com/archives/iphonetakeapart/
Good luck.
Dude dont do it!
buy a new one