Why would you want to? All the map templates provided by Mindjet have Mindjet as the author. When you use a template map this information is not changed to your name. If you send a map to someone Mindjet is the author not you.
How do you do it:
Design tab > Template Organiser > Dropdown to Map Templates >
Select map > Modify >
Right click map workbook tab > Properties >
Edit the author and save the map. Email and company will be automatically filled in from your File > Options > User Information when a map is created from this template.