You say "it" but you have multiple things that could be the "it", so in the end I am not clear as to what you wish to accomplish. Is the problem with the account, or is ultimately because you want to use the Mac yourself? There are different approaches to take depending upon what the ultimate goal is.
The support article If your Apple Account is locked, not active, or disabled - Apple Support has solutions for three frequently encountered reasons for an account to be disabled/locked/not-active:
● If a message says "your account has been disabled in the App Store and iTunes Store" or "You cannot login because your account has been locked”,if available you might be able to request reactivation by tapping Continue right from the alert. If that does not work, Apple provides a link for this specific issue. Tap or click here and choose a self-help or contact method ➞ https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362 .
● If your account has been disabled for “security reasons” the solution is to reset your password as outlined in this document: If you forgot your Apple Account password - Apple Support
If you find you can’t sign in, reset your password, or receive verification codes, you can request account recovery (read this support article: How to use account recovery when you can’t reset your Apple Account password - Apple Support ) to regain access to your account. More detail in —> Activation Lockout Issues - Apple Community For additional assistance from Apple Security, read: Contact Apple Support - Apple Support
● If your account says “Account [is] locked”, or it is inactive, you might be able to request access to your account by tapping Request Access right from the alert. If that does not work, this link (versus one taking you to the general support page) is the most direct way to get to the people helping you with this —> https://getsupport.apple.com/?PGF=PGF63005&category_id=SC0245&symptom_id=23626
or by telephone at one of the numbers in this support article --> Contact Apple Support - Apple Support
Additional reasons:
● According to various posts, Apple may permanently lock accounts for other reasons (very broadly outlined in section VII-B of Legal - iCloud - Apple ). That may be the case here if none of the previous reasons apply to you. If it isn’t apparent, contact Apple and ask if that is the situation, but don’t expect them to tell you why. You, or somebody who has managed to get access to your account, are likely doing something Apple is interpreting as account misuse. You will have to see if your activities could be construed—rightly or wrongly—as meeting any of Apple's conditions in the support article. You will need to create a new account and stop doing things the way you have been that may have caused the other account to be locked.
In this situation you may be able to still use your equipment with a new account. Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Check the requirements and steps at: Activation Lock support request - https://al-support.apple.com/#/additional-support Apple says, "Proof of ownership documentation is required," but does not detail what currently constitutes proof other than it “must include the product serial number, IMEI or MEID.” Apple may typically require the original receipt* issued by Apple or an Apple Authorized Reseller. If Apple resets the device this will give you access to the device but won't restore access to the account used to lock it. There is nothing that can be done to expedite an Activation Lock request.
*Apple recommends you "Keep your receipt after you buy an Apple device" --> Keep your receipt after you buy an Apple device - Apple Support
● If you deactivated your account, see the section about "Can I reactivate my account?" —> How to deactivate your Apple Account - Apple Support
Note that if you are trying to use another person's account you are violating one of Apple's fundamental terms of use and you may not be able to expect assistance from Apple in getting access to the account.
Legal - iCloud - Apple
IV. D. No Right of Survivorship
Except as allowed under Digital Legacy and unless otherwise required by law, you agree that your Account is non-transferable and that any rights to your Apple ID or content within your Account terminate upon your death. Upon receipt of a copy of a death certificate your Account may be terminated and all content within your Account deleted. Contact iCloud Support at iCloud - Official Apple Support for further assistance.
