Identifying them is a great start. There are then two routes to follow.
Either continuously challenge them by doing exercises to prove they're wrong. For example, if you believe you're shy, push yourself to do things you think only bold people would do. Slowly you'll start transforming into a bold person.
The new and improved way to dealing with such things is using NLP, hypnotherapy and/or Time Line Therapy. This would rid you of an insecurity in a matter of minutes.
Hope this helps. If you have any questions drop me a line.