Hi,
do you want to remove a value entirely, or would you just like to replace it?
If you would like to replace a value with another value, you can use =ReplaceList(findValue, replaceValue) in the SET activity. Please note that in case of using ReplaceList, the Key must be an attribute/variable containing the array.
If you would like to remove all values from an array, you can use =Clear() in the SET activity. Please note that the key has to be an attribute/variable containing the array as well.
Best wishes,
Kathy