Dennis, have you determined exactly where the hive is located ? As you mentioned, your friend will be tearing down this structure so it's not critical that you do a very neat job and open only what is necessary to remove these bees. However, it would be good practice on your part to be as efficient as possible if you intend to perform other cutouts down the road, but anyway... Can we assume that you will be trying to save this hive and relocate it ? As M.B. stated, even nice bees at some point in your cut out will get agitated, count on getting stung if you don't have proper protection and count on getting stung anyway, bee suits are not 100% sting proof. Don't let that scare you though. To me getting stung is something that just comes with the territory. Anyway, if you want to discuss this more, provide a little more information as to where they are located, wall or ceiling, etc... and type of interior/exterior. Good luck!