The Second Amendment isn't like other amendments. It's deeply and intrinsically embedded in the cultural and political identity of half the country, which makes the 2/3rds majority required to even hold a Constitutional Convention impossible, because those states will never vote to touch the Second Amendment. It has a multi-million dollar industrial lobby, all of the police, all of the military, and one of two effective political parties behind it. It's written in such a way that it justifies itself as existentially necessary, so that even attempting to amend or repeal it legally is certain to lead to civil war - a war millions of Americans have been stockpiling arms in anticipation of ever since the last one ended. Any Senator or Congressperson bringing it up is committing career suicide, and should they succeed, they'll have to spend the rest of their life avoiding open windows.

And then there's the problem of what to do with all of the guns already in the country. No one is confiscating them without a fight, regardless of what the law says.

So yes, it's technically possible in the same way open-heart surgery on yourself with a ballpoint pen is technically possible. Practically speaking, though, it means a lot of pain and a lot of bloodshed, and it's easier to regulate around it because at least then the US doesn't turn into Northern Ireland.