Upgrading NetBSD on Jornada 720

Hi.

I am currently running version 4.99.72 of NetBSD on my Jornada 720 and 
was wondering whether there is an easy way to upgrade to version 5.0?

I checked on the NetBSD website but the upgrade guide seems to assume 
that you've got a machine that boots/installs from CD.

Another quick question - to install sets can I just untar the binaries 
in ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-x.x/hpcarm/binary/sets/ to the 
root directory or do I need to use another program to do this?

Apologies if these questions have been answered elsewhere but I couldn't 
find anything regarding this on the net and I am used to using programs 
like freebsd-update and sysinstall on my PC but not doing things manually!

Thanks in advance,
Nick.