"When you install something, you expect to be able to remove it too. But when a reader came to uninstall BlueStacks, an Android emulator, from his Mac running High Sierra 10.13.2, he found the way blocked. The Finder kindly informed him that “The operation can’t be completed because you don’t have the necessary permission.”
"The moment that we see the word permission, all becomes clear: it’s a permissions problem. So the next step is to select the offending item in the Finder, press Command-I to bring up the Get Info dialog, and change the permissions. It does, though, leave the slight puzzle as to why the Finder didn’t simply prompt for authentication instead of cussedly refusing.
"Sure enough, after trying that, the app still won’t go and the error message is unchanged."