xorg upgrade advice

[Chuck Tuffli]

i'm in the process of upgrading a 4.7 system from Xfree86 to xorg from
ports and am running into some problems. the upgrade instructions
seemed pretty simple

pkg_delete -f /var/db/pkg/imake-4* /var/db/pkg/XFree86-*
cd /usr/ports/x11/xorg && make install
pkgdb -F

but the make fails in xorg-libraries when trying to install
expat-1.95.8 because expat-1.95.5 is already installed. looking back
through the build log, there is also a warning about upgrading from
libtool13 to libtool15.

for an older system like this, are there some additional steps others
have found necessary/useful?

---chuck