If you need more staffers than planned for a job, you can easily manage the posted event job. Even if you filled the positions requested in the event job.
(NOTE: If you are in need of for instance a waiter and only have a bartender event job posted, you will have to create a new shift).
To do so you need to log into your company admin click here.
When at your company profile, first click 'Jobs'.
After that click at 'Event Jobs'.
When you enter the next screen, choose the designated event job that you want to edit. It should look like this, posted in the image below.
Press the small arrows marked in the image below to add or withdraw the number of positions.
By pressing the arrow pointing up, you will increase the amount of Staffers, and by pressing the arrow down you will decrease it.
When you reached the desired amount of Staffers for the event job you are done.