While back when I wasn’t using a password manager like I am today I had a nasty habit of not remembering the password or the username or both for a particular wordpress site.
I am posting this because all of the other articles about this “trivial” task were a bit more complicated then they should.
The only way to get around this is to use a password manager like 1Password (Mac) or KeePass (PC) but if you forgot using them then you need a quick and dirty solution right there in the database.
The trick that Branko taught me is very simple:
Step 1.
Open up your php My Admin and in the wp_users table find the user you want account data changed and click on edit to start changing the account data:
Step 2.
To change a password it’s only needed to select the “MD5″ from the user_pass drop-down menu and enter your new password the way you want to enter it when you login to the site.
Step 3.
Log in with your new account data 
One question — why not reset the password from WordPress?
@Vladimir Because you can’t remember the password thus can not access the admin panel.
Great Technique!!
from CLI
#openssl passwd -1 123456
#mysql -p
connect db_wp;
update wp_users
set user_pass=’$1$QoGP/ZGE$UTJRa3S37hOFrashso1cy1′
where user_login=’admin’;