I followed this post to unload the old installation with these steps:
[sudo] npm uninstall -g @angular/cli
[sudo] npm cache verify
[sudo] npm install -g @angular/cli
The last step gave me trouble - the console screen just keep scrolling with this message, till I had to ctrl+C it.
gyp WARN EACCES attempting to reinstall using temporary dev dir "/usr/local/lib/node_modules/@angular/cli/node_modules/node-sass/.node-gyp"
gyp verb tmpdir == cwd automatically will remove dev files after to save disk space
gyp verb command install [ '8.1.4' ]
gyp verb install input version string "8.1.4"
gyp verb install installing version: 8.1.4
gyp verb install --ensure was passed, so won't reinstall if already installed
gyp verb install version not already installed, continuing with install 8.1.4
gyp verb ensuring nodedir is created /usr/local/lib/node_modules/@angular/cli/node_modules/node-sass/.node-gyp/8.1.4
I tried googling it and it seemed to be a npm versioning issue, but with no more useful info.