Shrinking a partition

[Colin Paul Adams]

I need to shrink a disk partition in order to fit the iso images on a
new partition.

I have used resize2fs to shrink my /usr filesystem from 20G to 15G (it
was only using 10G). This reported that it is now 3932160 4K blocks in
size.

How can I shrink the partition to match it, so as to free space for a
new partition? The resize2fs man page saya I can use fdisk to do this
but it doesn't say how. The sizes fdisk reports are clearly not 4k
blocks as they do not match the figures (it shows 27823288 as the
partition size). And I can't find a command to shrink the partition anyway. 
-- 
Colin Adams
Preston Lancashire