In 2012 Bitcoin wasn't worth a lot compared to today, so your private key may control a substantial value at today's rate. (You don't need to disclose it, not asking for it, keep your details private!)

I would go the much safer procedure that LoyceV suggested. Do not enter a private key on an online device which security you can't assess. There are so many ways to compromise your private key which non-security tech savvy people don't know about, that I highly recomment to play it as safe as possible.

NotATether's procedure is on an online device and requires a good understanding how Bitcoin transaction work to not mess up funds. If you spend e.g. only half of an UTXO to only one destination output address, the other half of your input UTXO will turn into transaction fee!

Don't know about your knowledge of Bitcoin's transaction model, but remember that a Bitcoin transaction consumes (destroys by spending) every transaction input(s) completely to the output(s) minus required transaction fee. Check for reasonable transaction fee at https://mempool.space.

This is important, don't skip to display a preview of your transaction details and check *everything* carefully. Never skip this step!