If you really want to properly remove the old cemented in posts, rent a jackhammer for an afternoon from your local tool rental business and break up the concrete around the post, it will all come out relatively easily once broken up and there won't be any place for kids, dogs or wildlife to hurt themselves on a cut off pipe mounted into cement.

If this was posted in r/dogs there would be pitchforks everywhere yelling animal abuse. lmfao.

edit: was/were?

I just use regular paper.

Find out why it's sagging and fix that issue first. Before you go Jacking up shit consider the fact that many times this will cause door closing opening issues as stress points are changing.

Sanding the door is NEVER the proper fix. There are literally TONS of diy videos re: this very subject.

Valid question.

A hand winch attached to that chain and the tow hitch of a vehicle will ease that sucker right off, and then allow you to back off the tension safely by backing up the vehicle. Your in the vehicle so no personal hazard.

edit: commonly called a come along tool.

This man doorknobs.