Hey there @Karla05364 - great question!

So, you have a single event type created, but you want to open up the availability on it? Easy day! =) 

When you set up your availability, you might have done it one of two ways: from your availability tab, where you would create a schedule then applied to the event type, or from within the event type itself using custom hours.

Whichever you might have done, you can then go back and edit that availability. 

Doing so - you can either alter your weekly available hours, add date specific hours - or both!

Check out the Loom video below for an example. I hope this helps!