You don't
This is part of linux. Permissions are a fact.
You can login as root, which gives you wide open access to everything.
However, this is a bad idea - if you typo - you might be reinstalling....so be careful
If you need to edit something that you don't have access to, do it as root.
You can do this quickly, by typing su at a prompt, and giving it the root password.
Make sure you exit when you are done editing, though.