II GS Super Expander GS4 (40MB HD on a card) question

["Giorgio Ungarelli" <giorgio@ungarelli.net>]

I have an Apple II GS, ROM 03, 2MB of RAM, 5.25 and 3.5 floppies.

I just bought a Super Expander GS4, 40MB hard disk on a card, with
controller (eBay auction #1268803070, to get a picture of the unit and to
see what it is).  The item is in "transit" between the seller and myself,
but I know I'll probably be posting this question as soon as I get the
above item, so here goes:

Does anybody have any info on how to install this internal hard disk and
any documentation (in electronic or other format) that could help me get
this up and running in my II GS?

Thanks in advance for any help.