how to update freebsd 5.4 to 6.1 via no Internet and CD or DVD media

[nectar76]

Hi, I have a USB WLAN Adapter, and have no idea to work on FreeBSD 5.4,  
but there is a driver called p54u (http://prism54.org/newdrivers.html)can  
try, but it is recommend to work on FreeBSD 6.

I done:
1. download freebsd 6.1 iso and unzip files, want to update system at  
local, but failed;
2. used  TortoiseCVS(CVS software for Windows) to download src/ from  
Anonymous CVS, copied them to /usr/src on freebsd-5.4, want to 'make  
buildworld', but failed; 'make' looks not work as usual;