how do I unlink my Microsoft account from my playstation 4 Minecraft on the computer

I am attempting to connect my microsoft account with my Ps4 account. My microsoft account is already connected to a Ps4 minecraft account. How do I find what Minecraft account is using my microsoft account and to disconnect it from it.

Even if you could disconnect it you wont be able to link a different Microsoft account.

Per https://help.minecraft.net/hc/en-us/articles/360037725571-Minecraft-for-PlayStation-4-FAQ

Note: Once a Microsoft account has been linked to a PlayStation® account, neither the Microsoft account nor the PlayStation™ Network account can be associated with a different account. 

If you choose to unlink accounts, then purchases will be returned to the account which made the purchase. Even after unlinking, Microsoft and PlayStation® accounts can only be re-linked to the original account.

Note: As of March 15, 2023, please DO NOT unlink your MSA from your PlayStation account via the in-game menu. You will be unable to link it back if you do so.

This is a restriction imposed by Sony.

I need to unlink my PlayStation Network account from my old Microsoft account which I don’t remember, & link it to a new Microsoft account to play Minecraft

You can unlink the psn account however you CANT link a different one.

Note: Once a Microsoft account has been linked to a PlayStation® account, neither the Microsoft account nor the PlayStation™ Network account can be associated with a different account. 

If you choose to unlink accounts, then purchases will be returned to the account which made the purchase. Even after unlinking, Microsoft and PlayStation® accounts can only be re-linked to the original account.

This is coming right from the Minecraft website

https://help.minecraft.net/hc/en-us/articles/360037725571-Minecraft-for-PlayStation-TM-4-FAQ

Hello ,

Thank you for posting on the Xbox forums. We understand that you are unable to unlink your Microsoft account from your PlayStation account. There is

a support article on Minecraft's support website which explains more about linking and unlinking the accounts. There is a risk involved with unlinking the accounts. The article talks more about the risks of unlinking the accounts. If you would like to continue
to learn how to unlink the account, we suggest reaching out to
Mojang support and PlayStation support. Be sure to let us know the results!

I think I'll go with the option of creating a new Microsoft account for now, and so then whenever the unlink ability on minecraft is working I'll fix my brothers account. But I thank you for your great service.

Kind regards,

Fellow Gamer

Hello TheLastPlatoon07,

Thank you for posting on the Xbox forums. We understand that you are unable to unlink your Microsoft account from your PlayStation account. There is

a support article on Minecraft's support website which explains more about linking and unlinking the accounts. There is a risk involved with unlinking the accounts. The article talks more about the risks of unlinking the accounts. If you would like to continue
to learn how to unlink the account, we suggest reaching out to
Mojang support and PlayStation support. Be sure to let us know the results!

Hello Savaged Wolf23,

Thank you for posting on the Xbox forums. We understand that you are unable to unlink your Microsoft account from your PlayStation account. There is

a support article on Minecraft's support website which explains more about linking and unlinking the accounts. There is a risk involved with unlinking the accounts. The article talks more about the risks of unlinking the accounts. If you would like to continue
to learn how to unlink the account, we suggest reaching out to
Mojang support and PlayStation support. Be sure to let us know the results!