Magnets are strongest in the direction their force flows. Pulling a magnet off a piece of metal by applying force in the exact opposite direction is the most difficult way to dislodge that magnet. Instead, slide the magnet parallel to the piece of metal (or slide the piece of metal parallel to the magnet face) to dislodge it. This strategy uses “shear force,” or an oppositional force that moves parallel to an object rather than perpendicular to it. A magnet is five times weaker when shear force is applied to the piece of metal than when direct force is applied.  With that said, dislodging a powerful magnet from, say, a metal pier beam still requires a lot of force. For that reason, if you don’t have experience dislodging extremely high-powered magnets, it’s best to start out with less power.