First Way “create a new admin account”
Reboot
Hold apple + s down after you hear the chime.
When you get text prompt enter in these terminal commands to create a brand new admin account (hitting return after each line):
mount -uw /
rm /var/db/.AppleSetupDone
shutdown -h now
After rebooting you should have a brand new admin account. When you login as the new admin you can simply delete the old one and you’re good to go again!
Second way “Resetting or changing your existing password”
If you’ve ever forgotten your user account password in OS X, All you need is to remember your username (you do remember that, right?) and then reboot your computer.
Hold apple + s down after you hear the chime.
sh /etc/rc
passwd yourusername
reboot
P.S. The only major downside to resetting your password this way is that you’ll lose all keychain passwords,
