Because WSL uses a standard Ubuntu installation, upgrading your packages should look very familiar:
$ sudo apt-get update $ sudo apt-get upgrade
You can aso upgrade to the latest version of Ubuntu with the following command (caution, this will take quite some time)!:
$ sudo -S apt-mark hold procps strace sudo $ sudo -S env RELEASE_UPGRADER_NO_SCREEN=1 do-release-upgrade
And, it works, just as expected!