HOW do I apply a patch to Solaris 7?

It seemed straightfoward enough. But, clearly I do not have any significant Solaris experience (I do have some other Unix experience).

I wanted to apply a sendmail patch (107684-08) to a Solaris 7 machine but failed. I was logged in as root. The "uname -a" cmd identifies the machine as SunOS 5.7 Generic_106541-07 sun4u sparc SUNW, Ultra-2.

Scenario:
(1) I downloaded the 107684-08 patch from one of the sunsolve.sun.com web pages and put it into the /var/sadm/patch directory.
I unzipped it which created a directory with the patch id as the name.

(2) This is the contents of the dir:
ls
README.107684-08   SUNWnisu/          SUNWsndmu/
SUNWcsr/           SUNWsndmr/         patchinfo*

(3) "Trying to install the patch:"

bash# patchadd ./107684-08

Checking installed patches...
rm: Cannot remove any directory in the path of the current working directory
/var/sadm/patch/107684-08
*/pkginfo: No such file or directory
One or more patch packages included in
107684-08 are not installed on this system.

Patchadd is terminating.

(4)After the failed attempt, the original directory had 0 contents.

(5) I tried to follow the README file's directions...
Please advise on how I can install this patch.