Suppose after you change your blog name you decide now you want to change the blog web address to match your new blog name. This is a very simple fix.

From the Dashboard, go to My Blogs.

At the My Blogs screen, move your mouse over the blog site you want to change until you can see and click on Change Blog Address.

At the next screen, you can enter the blog address you want in the New Blog/Site Address field.

Here, you will also have the option to create a new user name or match your username to the new blog address. You can select "No" if you don't want to change anything. Click Review my changes when you are done.

Finally, you are ready to confirm your changes. Click on I'm Sure to update your blog with the new address.

Now your blog web address will be updated.