Minecraft ACCOUNT? - 2

The e-mail via which my account runs in minecraft (on the PC) no longer exists and I can't answer the security questions that exist because the installation was years ago. I would like to change my e-mail but now I have no idea how. I appreciate any help.

If the email address no longer exists, you really have no choice but to create a new account. Security questions should be easy to answer anytime, anywhere. If you have given strange answers, then that's unfortunately your bad luck. At best, buy the game new.