Transfer domain from one ovh account to another OVH account

Hello,
My company created 2 ovh-accounts with different domains.
The situation:
1 account with example1.com domain and second account with example2.com domain. The idea is to transfer the first domain and all dns zone files to the second domain. And delete the first account. Like this we can manage all our domains with only one account.

I would like to know how can I merge these 2 accounts? I read documentation about how to change contacts (admin-billing-technical) but I am not sure it is what I am looking for.

Could you explain me the steps to follow to make this change?
Thank you