To give new members access to our GitHub repositories, invite them as members of the CUSail-Navigation GitHub organization under People (see below).
Here, you can also remove people who have left the team and manage who has each level of access to each repository.
To make a new person the owner of the organization (when a new lead is appointed), give them owner permissions. Also, make sure that their email is listed as the billing email under Settings (this is just for GitHub’s records, they won’t actually be charged anything).