Rotate the edge away from the wall and pull it straight out. This prevents scratching the blade's finish or dulling the edge. There is no truth to the rumor that magnetic knife holders will alter the steel used in knifes . There is however the fact that some magnetic strips will not hold on to a heavy knife. Make sure that the magnets are strong enough to do the job you intend them to do safely.
Many people are nervous about having sharp knives hanging from a magnet.
For them, the best way to store their knives is to build their own drawer rack. Some racks are commercially available, but not easy to find. The mistake I made was to purchase them from a butcher supply house instead of from a chefs supply store. They were razor sharp and felt good in my hands. Things I was told to watch out for.