One of the least published example of CRM code is deactivating an entity, probably because it's not used as often as creating, updating or retrieving entities. Below is an example I've used on several occasions to deactivate an entity:
public void DeactivateEntity(Guid entityId)
{
//variable initialization
SetStateDynamicEntityRequest deactivateReq = new SetStateDynamicEntityRequest();
//deactivate the cloned assignment
deactivateReq = new SetStateDynamicEntityRequest();
deactivateReq.State = "Inactive";
deactivateReq.Status = 2;
deactivateReq.Entity = new Moniker();
deactivateReq.Entity.Name = <entity name>
deactivateReq.Entity.Id = entityId;
//execute the deactivation request
service.Execute(deactivateReq);
}
