does anyone have an easy way to do this, without disturbing the 1.5.3
installation.
I have to have an automatic process to get this done.

so far I've found that rpm -U Firebird...rpm overwrites the
security.fdb (makes copy in /tmp first) and removes the firebird entry
in /etc/xinet.d. replacing the xinet.d entry still didn't work until I
rebooted

Ideal would be a way to upgrade the existing 1.5.3 if present and
install 1.5.4 if not,
but I can do my own if necessary