Hi, I have a large no. of websites in my excel sheet, they all are having wrong hyperlink. How to remove all hyperlinks, and what is the procedure to convert text to hyperlink.

For exmple.

I have yahoo.com on cell a1, but when I click on that msn.com is opening. I want to change its hyperlink to yahoo.com only. dont want to do one by one as there are more than thousands of websites avaliable. How can I do this on one go?

Thanks.
Sam