Change EAN

Can anyone inform me of the technical demand I need to make to Brand Reg support to enable an EAN change on an ASIN?

Please don’t answer that it’s not possible, because it is, when carried out the right way.

We have got so far with SS trying to run a ‘cleave’ process which failed due to some missing attributes. Recent attempts are getting the blanket ‘it is not possible to change’.

Any info on the exact process to follow would be much appreciated.