I forgot my password for Ubuntu MATE and I've read that the only way to reset it in Ubuntu is to enter recovery mode and enter a root shell etc. The problem is, I can't figure out how to enter recovery mode. Shift never works when I hold it down (it works when typing etc.) and I can't use sudo to, for example, force recovery mode to boot by modifying recovery.cmdline. I do have auto-login set, so I can still use the OS, but some stuff I'm doing requires sudo, therefore I need to reset/recover my password.
Any help would be immensely appreciated.
