modular xorg if X already installed

[newhouse%rockhead.com@localhost (Paul Newhouse)]

NetBSD 5-0 i386
pkgsrc 2009Q2

I found the how to about installing modular X if no ther X is installed:

   http://wiki.netbsd.se/How_to_install_modular_Xorg

I have another X installed, is there a guide on what special steps, if
any, that should to be taken?

TIA,
Paul