You can't (unless you commit suicide which I don't recommend as all methods are painful and/or carry a chance of going wrong and being unsuccessful). You can try cut out bad habits but that's all really.

Well I’d personally recommend a razor

Cut out the bad, expand on the good.

Nah a razor would still hurt and if you don't do it vertically or deep enough it's very slow and painful

can confirm this ↑↑

Uh.... to cut yourself out of your life....
Change your personality completely, your outlook on life.
Become an OPTIMIST.
There. Now you're no longer part of your own life. Someone else is.

And then very soon, that new person will become you.
It is the future.
There are no more humans. You are the last one.

I cannot say any more, they're going to try to delete these messages, but I've locked them in. Good luck, and godspeed.

Use kraft glue

If you stop talking to yourself you will eventually take the hint and leave you alone.

You kill the dark version of yourself in your mind. like that kermit meme.... kill the one with the hoodie. > _ > dur.