Digital BW, The Print

I'm a neophyte at B&W digital printing, and so happy to find discussion 
group that provides so much good information.  
    After following discussions here for a while, I purchased an Epson 1280 
printer and ordered a MIS spongeless cart kit with UT2 inks, which I received 
yesterday. The initial filling procedure for the carts seems straightforward 
enough, except that the empty black cart doesn't have a hole in the 
top--actually, it has a hole, but it is filled with what looks to be a 
non-removable plug that is flush with the top surface of the cart (no lip, unlike 
the plugs supplied with the 5-part color cart). 
    How do I fill the black cart?