What you will need ahead of time:
1) The new user's short user name.
2) The ld user's short name.
3) root enabled [Netinfo Manager -> Security pull-down menu -> Enable Root User (give it a VERY good password)]
Create the new user.
Log out of current user
Log in as root
Open /Users/oldusershortname
Drag & drop everything to /Users/newusershortname
Open Terminal (everything you type is case sensitive, make sure to get it correct)
Type in: chown -R newusershortname:admin /Users/newusershortname
Press Return key
Type in: chmod -R ug+wrX /Users/newusershortname
Press Return key
Log out of root
Log in as old admin user (none of your files will be there, so it will be as if it was a competely new user, the Dock will be set back to the defaults)
Open Netinfo Manager -> Security pull-down menu -> Disable Root User
Log out of old admin user
Log in as new user