Changing the Main Administrator is an easy process.
Keep in mind that when changing the Main Administrator it will not update the company contact and billing information. Here's how to change that information as well: Dashboard-> Account-> Company Contact Information and Billing Contact Information.
You must be logged in as the current Main Administrator to perform this task!
Within the Staff Module, go to:
Click on Administrator Tab
Select Edit next to the Administrator who will become the Main Administrator
Under the Account tab in their User Profile, select "Set As Main Administrator"
Select "Set As Main Administrator" again on the pop-up