To remove clamps and blades from pick up screwdrivers:
Hold driver with top depressed which extends blade. Grasp clamp and blade with other hand and turn until clamp is free from shaft. Either replace entire clamp with blade OR
take a small pin (paper clip end works well) and push carefully out the flat pin embedded in the clamp. Removing the pin releases the actual blade. Exchange the blade, aligning the flat side against the pin in the clamp. Reinsert the pin and with the top of shaft depresse,d screw clamp back into the shaft. When snug, unscrew 1/2 turn for clamp arm mobility.