"The operation can't be completed because backup items can't be modified."

How can I delete a folder backed up via Time Machine to a .backupbundle disk image? When I try to delete the folder, I get the error message, "The operation can't be completed because backup items can't be modified." I found a similar question, "How can I delete a file marked as backup item?" The accepted answer says that this is a bug that will be fixed in a coming update. Unfortunately, this answer was written in 2011 –– 11 years ago. I tried to comment on the answer, but I did not have enough reputation. > A little more precision regarding what you tried would be helpful. > "when I Delete the folder". Which folder? Is that on the source disk, > or is it in the backup? And how did you try to delete? Also what > version of macOS and what format (HFS+ or APFS) is the backup disk > image? /Volumes/Time Machine Backups/Backups.backupdb/MacBook Pro (Retina)/2021-05-02-065359/Macintosh HD 1/Users/brianschack/Transmission Downloads On the backup. I tried dragging the folder to the Trash in the Dock. macOS Big Sur 11.2.3. Mac OS Extended (Case-sensitive, Journaled). > The accepted answer on your linked questin is basically wrong. The > highest voted answer is correct - you are trying to delete from a > protected area. You cannot just delete Time Machine files from Finder. @Ryccardo wrote the highest-voted answer to the question, "How can I delete a file marked as backup item?" He says, "[L]ocate the item in the 'in space' Time Machine view[.]" This is a backup of a computer that I traded in. When I go to the in-space Time Machine view on my current computer, it shows me the backup of my current computer –– not the computer that I traded in. He also writes, "There exists a helper program (command-line binary) [...] which allows you to supply a command and argument to completely bypass the access restrictions." When I navigate to /System/Library/Extensions, I do not see TMSafetyNet.kext. In a different answer, @Evan Kroske writes, "It seems like the bypass program doesn't exist on Big Sur." How can I delete a file marked as backup item?