How to remove all the non numeric characters from column in mysql in bulk data

I want to remove all the non numeric characters from the column. I have bulk data in my database.

Currently I am using method as describe in below link:

http://venerableagents.wordpress.com/2011/01/29/mysql-numeric-functions/

The problem is that its taking too much time for preocessing.

For 1 million of row current logic takes 1 hour to process the data.

please help me..

Thank You, Ronak