Does anybody have an HP Photosmart C4480 all-in-one printer?

I am a bit that on this past weekend I was unable (SHH!) to change the print cartridges for this (I ended up calling it a) beast.

It was for an elderly friend, and though he had a manual for it, listed as C4400 series, it seemed to be at odds with the hardware itself. And it's the only one I can find on-line.

For instance, the picture in the manual showed a sort of carriage to place the two ink cartridges into, but there was no such contrivance in the machine. I even asked the chap if he had thrown it out with the old cartridges.

Does anybody know how (the hock!) to change cartridges for this printer?

Thanks, Am.