Publishing via Lightroom/Bridge

For some time I seem to have had two Adobe Contributor accounts unknownst to myself.  Up to now I was uploading stock directly via the contributor portal. It works fine but I would like to upload via Lightroom Classic. When I try to do this the files get sent to a Contributor Account which is not the one with all my assets in it. I would like to stop Lightroom uploading to the account it is currently linked to. How do I break the link? How can I delete that stock account and start afresh via Lightroom with the contributor account where all my assets are? I reckon it has to do with the fact that my photography plan is linked to the contributor account in which I have no assets but just don't know how to switch these contributor accounts so that Lightroom will feed into my established collection.

Thanks for your help!