Shutdown your Mac
Then, press and hold the “Option” key as soon as you hear the startup chime.
When the boot menu appears, release the Option key and and select the “Recovery HD” disk in the boot menu.
Wait for “OS X Utilities” menu to appear
Click on the “Utilities” option in the menubar and select “Terminal”
Type the following at the prompt:
and press Return on the keyboard.
Select the Macintosh HD volume and the user account. To change the password, type it in both places, and a hint, then click the Save button.
Restart your Mac and, hopefully, login.If you continue to have questions on this topic, just reply back to this discussion. I will be more than happy to work with you further. Hopefully, this info will answer your question.
If so please, please remember that when you are asked to give a rating, you are rating my personal service only and not this website itself or your issue.
Thanks and good luck,