Sometimes a process gets generated in LeadSimple by mistake, or circumstances change, and an entire process needs to be cancelled. This is something that should only be done when you are absolutely sure that the entire process needs to be cancelled, not just moved to another stage or edited. Once a process is moved to a cancelled stage, no more tasks will generate and no more reminders will be sent, so it is very important to make sure that this is done only when absolutely appropriate. In most cases, this should only be done by a senior manager.
That said, when you need to cancel a process, the way to do that is to change the "stage" of the process in LeadSimple to the appropriate cancelled stage. The video below shows how to do this in detail. If you do not see a canceled stage in the process that would be appropriate for the cancellation reason, then talk to the CEO to get the process modified.