regain control of compromised facebook account

how to regain control of your compromised facebook / messenger account:

assumptions:
- you are still logged in
or
- you can still log in
to yout facebook account.

while logged in in facebook:

1.  CHANGE YOUR PASSWORD
1.1.  Menu (hamburger icon / three stacked horizontal lines icon / gear icon)
1.2.  Settings & Privacy
1.3.  Settings
1.4.  Password and Security
1.5.  Change password
1.6.  Current password

1.7.  New password
1.8.  Re-type new password
1.9.  Update password

2.  LOG OUT ALL SESSIONS
2.1.  Menu
2.2.  Settings & Privacy
2.3.  Settings
2.4.  Password and Security
2.5.  Where You're Logged In
2.6.  See All
2.7.  Log Out of All Sessions
2.8.  Log Out