After you create an allocation, you can delete it, change the assigned resource, unstaff it, or change the allocation role.
You delete a single allocation by right-clicking on the allocation and choosing Delete Allocation:
Deleting an allocation will also delete any associated task schedules. If the allocation has any time tracked against it, the time will remain but will be unlinked from the allocation.
Use the Re-Plan wizard to bulk delete allocations.
You can unstaff an allocation (remove the resource) by double-clicking the resource name and deleting it. Then click Update. Unstaffing an allocation will delete any associated task schedules. If the allocation has any time tracked against it, the time will remain but will be unlinked from the allocation.
You can replace an allocated resource by double-clicking the resource name, clicking the button and selecting a new resource. Then click Update. Any task schedules are transferred to the new resource.