The last time I was at that particular site, there was a restaurant there. Since then, someone had installed a high-security cylinders on the doors and I knew that I had very little chance of picking those cylinders or drilling them. On the inside of the doors the locks were operated by thumb turn. So I focused my efforts on that thumb turn in order to open the door.
I use the short end of a Z tool from my automotive opening kit to manipulate the thumb turn and unlock the door. It took a little effort to get the tool between the doors, but once I had the tool inside, it was a simple matter to flip the thumb turn, open the door, remove the cylinders, and install new cylinders with a standard keyway. Check out this company link if you are looking for a similar service for your business.
