Removing crown on tooth which had an apicoectomy done in the past

It sounds like this tooth has been through a quite a bit over the years.  From past experience, I would say there is a 50% chance that there is insufficient tooth under the existing crown once it is removed.  If this turns out to be correct, then you would be looking at an extraction and implant in the future.  If the amount of tooth structure turns out to be suffice, a new crown could be placed.