FTP on Solaris is normally enabled by default. Have you tried FTPing to the box?
If it's disabled you need to make sure there are entries for it in /etc/services:
ftp-data 20/tcp
ftp 21/tcp
and /etc/inetd.conf:
ftp stream tcp nowait root /usr/sbin/in.ftpd in.ftpd
If you edit either of these files you need "kill -HUP" the "inetd" process (or kill it and restart it).
You can create a directory for the software if you want, doesn't matter, it's up to you. You can do it from within FTP or otherwise.