Please explain a bit further as to what you mean by 'removing a lost password'. It seems from your post that you are referring to an email on an Email account but I don't know why that would need to be 'removed'.

Please also include a screenshot of any errors that you have received to help us understand the problem.

There is only one question that you have submitted here so no one has suggested any action for you to take.

https://support.mozilla.org/en-US/kb/protect-your-thunderbird-passwords-primary-password#w_reset-your-primary-password-if-you-have-forgotten-it

Alternate method: close TB, open the profile folder, delete or rename key4.db, cert9.db, logins.json, restart TB, enter account passwords when prompted.

BY the lost PASSWORD I AM REFERRING to the LOGIN mail THUNDERBIRD PASSWORD !! Of course the password I believe I used now no longer works -- and programming suggestions such as MOZILLA instructions on how to remove or replace the PASSWORD also do not work for me ??? I'm an old USER -- Not a PROGRAMER !! Thank you -- Access to Thunderbird is no longer available to me so I guess it is time for me to use another email client !!!

Your post makes no sense to me and everything you said makes me believe whatever it is that happened would have happened exactly the same if you had been using any other mail client.

Something you seem to be missing is that passwords are meant to prevent others who don't know the password to do whatever it is that knowing the password allows you to do. It it was possible to ignore or bypass a password when you forget it, then it would also be possible for anyone else to do the same, and the password would serve no purpose other than annoy the user that has to use it…