i have a new mac - ade autorised - but my books connected to an ?other vendor account... where i can change that?

i have a buy a new mac - bevor i have a pc - on the mac i have setup ade4, with adobe i have autorised my mac and my trekstore (trekstore i have before connected to my pc) - after adobe the authorization has work on tekstore and the new mac) but when i will copy a buyed book to tekstore i receive the following error - ce_copy_not_allowed - when i double-click on a book i see the following problem

my book is connected to an other vendor account i musst connect to my account - but i don't know where i can change that? any good ideas? - many thanks for your help - best regards susi