After downloading the tar to /tmp, to install portage:

mkdir -p /tmp/portage
cd /tmp/portage
/usr/bin/tar xpf /tmp/portage-solaris-v8.tar
./install-sparc.sh help
./install-sparc.sh

This software is written, developed and maintained by
Jason Wohlgemuth and Sunil Kumar. This software is 
mirrored here until both pass the gentoo developer
exams.