upgrading from 6.3 to 7.3

[junklist]

Hello!

I have a box running FreeBSD 6.3-RELEASE-p15 and I would like to upgrade 
it to 7.3. As far as I know I cannot use freebsd-update to do this since 
it is not supported any more. so:
1. The only other way I can upgrade to 7.3 is using update from source, 
isn't it?
2. What upgrade sequence should I use: 6.3 -> 6.4 -> 7.0 -> 7.3 or 6.3 
-> 6.4 -> 7.3 or even 6.3 -> 7.3 would work fine?
3. Will I be able to use freebsd-update with 7.3-RELEASE if build if 
from sources?

Thank yo for your time and effort!