I can't access my iMac because I have lost my password

[iMore Question]

When I follow instructions to press power button plus control r
the system does not show Terminal

 

[Rob Phillips]

Welcome to iMore! You need to press and hold COMMAND-R directly after pressing the power button. Hold down both of those keys until you see the Apple logo.

 

[pansen]

I have lost my password and at the password screen there is no 'retrieve password' option.

 

[Rob Phillips]

I have lost my password and at the password screen there is no 'retrieve password' option.

This should help: https://support.apple.com/en-us/HT202860