I'd be interested in better answer than the one that I have.  (I've
encountered this question before!)

I played around for hours trying to get the darn thing to install to an
alternate directory (I'm an AIX guy, not an HPUX guy), and finally just
settled on creating a soft link at the default location that points to the
location that I want to install to.  Basically, create the install folder
that you want, create the soft link at the default location (was it /adsm or
/usr/adsm? I can never remember), then install the package.  Works fine.

Paul