Freeing up space on My book live

I have a 3TB My Book Live and have been using Acronis True Image to automatically back up four PCs on my home network. It’s worked well so far, but I just consolidated two of the PCs into one and want to free up space deleting the back ups from the retired PC. How do I get rid of those old back ups?

MBL is now a security risk so you might want to find a different solution

Yeah - I heard that. Is there no way to disable just the internet/web access to the MBL and let it be used just on the LAN?

Unfortunately not