Degraded message. Now what?

Hope someone can help me here.

I received My Book World Edition II 4TB yesterday from Amazon. Everything was going smooth but now I have a message:

DataVolume Mirror    43% 1.82 TB Degraded 

I have a replacement already on its way. What is the easiest solution now? How do I replace the drive and after I replace how to I rebuild the information?

Right now I can still access all the data…thank god.

Any documentaion would be appreciated as I can’t find anything with the manual or pdf file that came with the drive.

My guess is that it heated up while transfering all the huge .mkv files.

I know they are not fan cooled…is this something I should be concerned about as I use this drive as a media server.

Thanks in advance.