Help! My 1 TB is nearly full

WD Legacy Products My Book Live
2

Look for the debrick guides, you can follow those to upgrade the hard drive if you wish to do so. Also a few threads already cover that topic such as  http://community.wd.com/t5/My-Book-Live/Replacing-hard-drive-in-My-Book-Live-NAS-Cloud-Storage/m-p/800775#M30010

Or, if you want another MBL/NAS device, just buy it and connect it to your LAN, just make sure they have different names.