Inventory: Remove stock amounts; no transactions

I have a need to remove the current quantity from item stock.  The quantity were incorrectly imported.  This tenant has been inactive.  We have sales or purchase transactions.  What is the best or easiest why to zero out the quantities.  I was thinking of doing an inventory adjustment or use the physical count.  There are financial issues since the tenant has not transaction.  The amounts were imported.  

I appreciate any assistance or advice on the best way to handle this issue.