How to uninstall Messages

Not possible. None of the apps installed with Mac OS can be deleted because they are installed on a read only, sealed portion of your hard drive where no alterations to any files there are allowed.

You can turn off iMessage or not use it or add Screen Time restrictions, but it cannot be removed.

Contact Apple directly here, before you throw it out the window:

Contact Apple Support - Apple Support

You have a choice of either Chat or Phone support.

• For Chat support use the Online Support option and describe the issue. You are given the typical Support Articles related, but more importantly on the bottom of the screen is a button to click form "More Options". That is where you will be give the ability to start Chat support if it is available in your region. Since you are not using Messages on this Mac, this is not what you would likely be using.
• For Phone support, there is the usual phone tree of AI suggestions. I recommend just saying "Speak to Live Agent" to deal directly with a human.

iMessages has started asking me to sign in. But I have NEVER used it! And it's showing an old email I haven't used for over 7 years!! I can't sign IN because I don't use it and don't want to. The popup requesting I sign in WILL NOT STOP. Help please!

Does this happen on device restart or continually during your current session?

If on restart or startup, then go to  > System Settings > General > Login & Extensions, and make sure Messages is not showing in the Open at Login box on top of the screen there. If so, you can remove it.

Also go to  > System Settings > [name on top] > iCloud > Messages, and make sure it is showing Off.

Are you able to access Setting in the Messages app after launching it. If so, go to Settings under the Messages menu and under the iMessage tab, uncheck Enable this Account. If you don't have the Password to login there, you may not be able to change any of the Settings.

It is unchecked for startup. It pops up every five minutes asking me to sign into to iMessages with old email. And sometimes it will NOT CANCEL the popup message at all. When that happens, I have to restart my laptop. It is driving me nuts.

There MUST be a way to shut this thing up!!! If not, my next action is throwing this laptop out my window. 😜

Thank you so much. I was able to speak with Chat support who escalated it to Supervisor who called me and connected onto my MB Air. They confirmed it was odd and they simply disconnected it from their end. All my settings were correct. We suspect it is the new Golden Gate 27.0 since the issue started around same time it updated.

I'll always be a Mac person because their tech support is GLORIOUS. In the past 35 years in tech, I've only needed help a 4-5 times and they have ALWAYS been the most efficient and nicest folks EVER to deal with. It is SMART to hire good people and pay them well. They will, in turn, hold Mac clients to the brand.

I appreciate your help very much, Jim. :-)

Great to hear and thanks for the update!