Pins in headphone jack pushed inside, is it possible to remove the metal sheath and fix them So one of my MacBook pros headphone jack's pins has been pushed inside, and no amount of using a toothpick is fixing it, so it's it possible to take apart the computer, remove the metal casing for the headphone jack and push the pins back?

It's an old laptop (2012) so it's not covered by warranty.
You can open it and have a look but the iFixit guide MacBook Pro 15" Retina Display Mid 2012 Headphone Jack Replacement shows this as the ($30) replacement part and it looks to be made of molded plastic.  If yours is too you won't be able to get to the inside.



Alternatively you could get a USB to headphone jack adapter - they start from under $1 on ebay.