Linux Mint also uses apt as a package manager. Similar to Ubuntu and Debian, you need to edit the paths in /etc/apt/sources.list and /etc/apt/sources.list.d/*. For some sources from Ubuntu and Debian, you can refer to Ubuntu Help and Debian Help for modification.

You need to modify /etc/apt/sources.list.d/official-package-repositories.list (note the backup), and replace packages.linuxmint.com with the mirror source:

deb {{endpoint}}/ {{release}} main upstream import backport

Then run apt update.

Note: After the completion, please do not use mintsources (the built-in graphical software source setting tool) to perform any operations, because after the operation, mintsources will copy /etc/apt/sources.list.d/official-package-repositories.list regardless of whether you press "OK".