Damn, that will be two days of walkie calls "Is there an ad sign for ________." and price reductions. They are going to hate you. Especially if your area has any high priced items.
well with the right login credentials you can do it from Store Apps(IIRC that's the name but could be different) on a computer much much faster and the potential for further mayhem is untold.
unlocate product
delete all locations
hide all the labels (do not destroy or toss into trash, just make them slightly difficult to find)
switch back endcaps and front endcaps
change all custom blocks
etc etc good jolly times can be had.
just don't do most if not all of this as it is not the management that'll have to fix it it'll be drone #156 and #175 doing the dirty work to put it all back.