How to remove/reset Windows Subsystem for Linux on Windows Insider Build 14316
The following answer only applies to WSL on Windows 10 1703 and 1607. WSL on Windows 10 1709+ can be installed from within the Windows Store UWP application.
If you want to remove and reset the Linux subsystem, open a command line prompt with elevated permissions and enter the following commands:
lxrun /uninstall /full
lxrun /install
Sources:
https://www.slightfuture.com/technote/lxss-lxrun
Installing Fish Shell on Ubuntu on Windows 10
HOWTO: Ubuntu on Windows | Ubuntu Insights