Sometimes there isn't enough room to pull both pads out at the same time. If you can't squeeze the tabs and pull them out together, just grab one and pull it out, then the other. Make sure you get the little spring clip/retainer piece out with them when the second pad is out. put the new pads on the clip and squeeze them together and then put them in place. You will hear an audible click when they snap into place. If you do it wrong then the pads will be too close together and the rotor disc won't fit in. My only other suggestion is to try and keep your fingers and any dirt/grit/oil off of the pad surfaces and the rotor surface