You have created a sub-domain for example: http://lawthinkers.com/mywordpress/ but if you want to keep the sub-domain name at first of the main domain name like http://mywordpress,lawthinkers.com  then the process is not difficult at all. Just follow these steps:

* Go to your Dashboard and at the very left-bar you will find setting.

* Go to Settings>General

*Can you see the “Site Address (URL)”. Here you have to type the sub-domain name before the main domain name. For example” if the name is: http://lawthinkers.com/mywordpress/ then you have to change it like this: http://mywordpress.lawthinkers.com.

* Now click on “Save Changes”.

It’s done. See, it’s very easy to change the format your sub-domain name.

***Caution: Do not change WordPress Address URL from the settings. If you do so then your site won’t work. So be careful and change only Site Address URL from settings. If you unfortunately change WordPress Address URL you have to follow my blogs for solutions.