23-041 roller track removal
I'm actually not sure what the trick may be. This kind of track is usually installed using simple screws. However, this is obviously not the case for you. Those look like rivets or nails or something. I'm afraid I can't guess what they may be, but I can tell you it's not normal. Whoever installed these must have used whatever they had on hand to put these in the floor.
My instinct is to tell you to drill them out, but depending on what they are that could be a bad idea, or at the very least ineffective. You may want the help of a local professional to come out and look at them for you. Sorry we couldn't offer a better solution!