lifting up carpet on stairs with metal scuff plates?

Just wondering, how do you remove carpet on wooden stairs? On the edge of each stair there is a metal plate like a scuff plate. The plate is very hard to remove, I tried to get a metal flat head screwdriver under the plate and it didn't budge! I don't want to ruin the wooden floor underneath. The carpet would of been laid in the 1950's, if that helps

Any one with any suggestions for me would be much appreciated ?