Epson WF-C20590 User Manual page 308

3. Push in the tabs on the staple cartridge and lift it up to remove it from the holder.
Note: You can remove the staple cartridge from the holder only when it is empty.
4. Insert the new staple cartridge into the holder as shown and push it down firmly.
5. Insert the staple cartridge holder back into the finisher unit and push until it clicks into place.
308