Follow this link. It is comprehensive and to the point.

http://hodentek.blogspot.com/2012/04/installing-sql-server-express-2012-and.html

Installing SQL Server Express 2012 and managing the LocalDB

This article discusses in detail with a number of screen shots the installing of SQL Server Express 2012 with tools (x64) on a Toshiba Satellite P775 Laptop computer (x64 bit). The article goes on to describe how to manage LocalDB using the SQLLOCALDB utility.