It is correct as is.
After downloading OpenACS to your tmp directory you move into the directory it is supposed to be in:
cd /var/lib/aolserver
you untar and decompress the files in the tmp directory:
tar xzf /tmp/openacs-5.1.5.tar.gz
and you move those files to the destination (the directory of your choosing, service1 represents that name):
mv /tmp/openacs-5.1.5 service1
Should you be able to edit the documentation? Yes. That is the whole point of moving to a wiki based documentation. Making it easy for new users to change/fix the documentation.