It's pretty simple: the bot is attached to a Facebook Fan Page, so in order to transfer ownership, current bot owner should grant the person who's about to become the new owner the 'Admin' Page Role on this Fan Page and the 'Admin' status in ManyChat. You can use this quick guide below:
1) Open your FB page connected to ManyChat and go to Settings.
2) Choose "Page Roles" tab:
3) From here you can Assign new Page Roles to whomever you like (the person doesn't even have to be in your friend list) - just type their credentials and click "Add" button:
4) Since we're done with the first part, let's go straight to our ManyChat account and click Settings:
5) Navigate to the 'Users' tab and click the big blue "+ Invite New Member" button on the right:
6) Choose the member's Role and click "Generate a Link" button below:
7) Copy the link and send it to the person you wish to grant 'Admin' status to. Remember that the link expires in 24 hours, but you can always create a new one in the very same way.
8) After this person follows the invitation link and becomes an Admin in the ManyChat account, you can then transfer the ownership of the ManyChat account to them by clicking on their ManyChat role and clicking 'Make Owner'
And we're done - hopefully this helps!