How to restore an old domain which was redirected using 301

     

I have an old version joomla website in the domain http://www.companyname.com and a new version of joomla website http://www.companyname-test.com



Old version was redirected using a 301 redirect. So if we enter the url   http://www.companyname.com it redirects to http://www.companyname-test.com


Now we are looking to restore the original url (http://www.companyname.com) with new contents in http://www.companyname-test.com


What are the steps to follow?


      
  1. Do I need to undo 301 and copy the contents from new domain to new domain?
  2.   
  3. Will it be possible to rename the domain name?
  4.   

Please help to proceed further. Thanks in advance