about freebsd partition problem

[t s]

Dear all,
i have some partition questions in freebsd installation!

my harddisk(40G FAT32) :
c:\ (primary 10G windows XP root)
d:\ (logical 5G with data)
e:\ (logical 5G with data)
f:\ (logical 10G with data)
g:\ (logical 10G empty)

so i want to release 500MB from "d:\" for the second primary partition
and then put the freebsd "/" on it, the other put to "g:\" just like the
belows:

windows xp mode
c:\ (primary 10G windows XP root)
d:\ (logical 4.5G with data) ====> 500MB for freebsd "/" (second primary
"ad0s2")
e:\ (logical 5G with data)
f:\ (logical 10G with data)
cannot see the g:\ ==========> used by /var /usr /swap

is it ok??? but i don't know how to create the "ad0s2"??? and edit the g:\
for /var, /usr, /swap???

any disk edit tool can do it???

thank you very much

steve (come from hong kong)