Facebook is constantly updating its script and system to help improve the user experience on the website along with providing them control over their profile and information available on the popular social networking site.
One of 
the feature of Facebook is that the user can manipulate his or her profile wall with these options mainly:
- show wall to everyone (including those who are not friends)
- show wall to friends only
- hide wall from everyone (including friends)
To customize these options follow this tutorial. (This tutorial basically focuses on how to hide your wall tab from everyone, thus removing it from your facebook profile)
1. login to your facebook profile
2. goto: (top right menu) Account > Privacy Settings
3. Click on customize settings on the page that opens
4. Find the first option saying:
Posts by me
Default setting for posts, including status updates and photos
and click on the options list available in front of it.
5. From the drop down, select custom
6. In the custom popup box, saying:
Make this visible to
These people
and from the drop down select Only Me
7. Save settings and preview your profile from any of your friends profile to confirm that changes has been made!
I follow all the steps and finally successful in removing the button. Thanks.