If you are having difficulties priming we have created two videos which show how to prime sponge type cartridges. I will include the two youtube links below.
IF you still have the caps that came installed onto the cartridges you would be able to re attach them onto the cartridge and use a syringe and needle to withdraw from the sponge.https://www.youtube.com/watch?v=2ccxMBaSUQI
If you do not have the caps you are able to use a syringe to push air through the ink tanks to the cartridges.https://www.youtube.com/watch?v=fg2lk4lou2Q
I believe the first video would be the most efficient way.