HP a400n drive cage - how to open?

I'm trying to add a drive to a friend's HP Pavillion a400n. It has an oddball HDD cage mounted vertically against the front of the pc case, perpendicular to the other drives. I figured out how to get the first drive out, but the empty second space beneath it is the one I need and I haven't been able to decode how to get it open. :confused

Hours of Googling have only turned up one HP document that, oddly, shows the cage but ignores it; the section on HDD replacement shows the HDD in the usual place right under the floppy, rather than in the vertical cage.

Can anyone direct me to the correct procedure online? Or just plain tell me how to do it?

tia

 

http://h10032.www1.hp.com/ctg/Manual/c00225826.pdf

The manual I'm looking at shows you can put a second hard drive under the floppy, but if you look at the diagram it also shows how to remove that green cage where the hard drive is mounted stading up

look on page 14 thru 17 of the diagram it appears to show you how to take it out. I haven't tried it myself but it looks like it will work.

 

Thank you Buggabear, but that was the doc I was referring to. My friend Markster found the correct doc, with much better info, here:
http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&cc=us&docname=c00510352&dlc=en&product=391284

All better now. Again, thank you.