@JONCHGO Welcome to the forum!
There is no easy way. You have to go to each website, and initiate a password change procedure. It helps to set up the new password in the corresponding Bitwarden vault entry first, and to the transfer the new password into the password change form using the auto-fill function.
Please refer to this post for step-by-step instructions on how to change your passwords.
What should I do if the website is dead?
In that case, it doesn’t matter, as long as the password you used on the “dead” account is not also used for any of your “live” accounts.