Navigate to the chosen event and first you want to split the event from todays date (the date you are making the changes on) to ensure previous bookings are not affected. After this has been done, select the pen icon, scroll to where it states "Is Event Happening Daily or On Specific Days Of The Week?" and select "weekly" from the dropdown, the days of the week will then appear underneath, here it is important to only tick the days of the week you DO want to include on the event. Once they have selected, scroll to the bottom of the page and press the blue tick. This will save the changes.
If there are any future bookings, this will prevent the changes from being made, in this instance you will need to decide what should happen with the bookings that are in the future and not on the chosen days of the activity.
Watch the step by step video on how this is done below.