curiosity via 902

Can I ask if there is no BM Via when buying a BM advertising account and granting 902 administrative rights, can Via 902 remove the old administration from the advertising account?

You should buy BM full via, and when you add a new admin to BM, after 7 days you can delete another admin, depending on the BM, it needs a second admin to confirm because you are new. Or you can also ask them to leave BM when you have fully back up