When your guides earn certifications and are ready to lead more trips, you can easily update their categories so they're able to be assigned to more trips. There are two ways to update your guides' categories.
Through Users:
Go to Company Settings
Click Users
Click the calendar icon
Click the Update button
Select the new categories
Click Update
Through Guide Timeline:
Click Guides, then Timeline.
Select the Guide's name you want to edit.
Click Update.
Select the Category from the dropdown menu.
Click Update.