Taking an artist off a date, or reshuffling who plays which date, is done per date rather than across the whole booking. What's possible depends on whether invoices have been issued.
Before you start: check for invoices
An artist cannot be removed from an event that already has invoices issued. Open the booking and check whether any invoice exists on the date in question.
If invoices have been issued, you have two options:
Void the invoices first, then remove the artist. Read the settlements and payments articles before voiding anything that has already been paid.
Leave the event as it is, delete the extra event, and represent that performance as a schedule entry instead.
Change the lineup on a date
Open the booking.
Go to the Artist & Location tab for the specific date you're changing.
Make the change on that date only, then save.
Repeat on each date you need to change, one date at a time.
Do each date on its own Artist & Location tab. Reshuffling artists across dates in one go can move the whole lineup rather than just the date you meant to change, and untangling that afterwards takes longer than doing it date by date.
Good to know
A booking with a signed contract or an issued invoice is restricted, so if a change won't save, that's usually why — check both before assuming something is broken.
Removing an artist from a booking doesn't affect their roster entry, and removing them from your roster doesn't remove them from existing bookings. The two are separate.
There's no change history you can pull up yourself showing who added or removed an agent or artist from a booking. If you need to know what changed and when, start a chat from the messenger with the booking reference and the date range you're asking about, and we'll look it up for you.