Transfer of WP from sub-directory to root

Have a look at Moving_WordPress.
Might also check Giving_WordPress_Its_Own_Directory.

Hope those help.

Do you want to move all the WP files or do you want just to display the blog at root – while leaving the install in a subdire?
If the latter – http://codex.wordpress.org/Giving_WordPress_Its_Own_Directory

If want to move everything: http://codex.wordpress.org/Moving_WordPress