Hi Rogue_Mango, sorry for the delay replying your post has seemingly been buried in between other posts so apologies for that.
Usually players are able to do unlink their console platforms through our website here, if you scroll down the page to linked platforms you can hit the unlink button -
https://account.ubisoft.com/en-GB/account-information
When you next launch a new Ubisoft game from your new PlayStation account it should ask you to sign into your Ubisoft account, which you can so so and link your new PlayStation account.
You can also do this by again visiting the Ubisoft account website and signing in using your new PlayStation account credentials -
https://account.ubisoft.com/
If for some reason you can not achieve this, we can unlink your 1st party platforms for you and relink another, however we are only able to do this once for you, so please make sure you are certain which PlayStation or Gamertag you want to associate with your Ubisoft account.
You can contact us through these channels to do this if you need any help -
Twitter Support -
https://twitter.com/UbisoftSupport
Facebook Support -
https://www.facebook.com/UbisoftSupportUK/
Ubisoft Support Website (for email support or Live Chat) -
https://support.ubisoft.com/en-gb/Cases/New