Old account deletion to unlink my xbox account

iSpiteful1210  Since you have access to your Xbox Account, (and you don't wish to keep the EA Account its currently linked to), you should be able to sign into your EA Account page via your Xbox Account here:

From there, its a matter of clicking on "unlink":

EA Account | Connected Accounts

Note:

• If you're unable to unlink your Xbox Account from your old EA Account, (such as if it asks for 2-Step or email Verification), you would need to contact EA Support.
• Any Apex progress and data obtained while playing on your Xbox Account is tied to your old EA Account, (which means it won't transfer anything, (such as your cosmetics), over to your current EA Account when you manage to link the Xbox Account to it).
• If you're still wanting to keep the old EA Account's progress and data, you would need to contact EA Support about changing the email address on the old EA Account to one you have access to.
• It is also not possible to merge game progress from two EA Accounts, (but you should be able to request a merge of the two EA Accounts here).
• If you truly wish to delete your old EA Account, (despite it meaning that you will lose your Apex progress and data), that also requires contacting EA Support, (which you can request your account's deletion here).