merging data in partitions - what's the procedure?

[Canon <seti sympatico ca>]

I'm not sure if this went through last time, so I'll re-post to make sure. 
Accept my appologies if this is a double-post.

I have a bit of a conundrum. I installed RH9 a while back and created 
appropriate partitions only to find that one of them is growing low on space 
so I was thinking of merging two partitions.  Here's my present setup:

hdb1 = /boot
hdb2 = /
hdb3 = swap
hdb5 = /home
hdb6 = /home/data
hdb7 = /usr
hdb8 = /var

The data I need to merge is in hdb7 and hdb2 partitions since my /usr 
partition is filling up rapidly and I have only 1% usage of my "/" partition.

Technically if I move /usr to my / and change the fstab values would that 
work? or are there some sort of associations to worry about.

BTW, how would I move all of /usr to /? 
(login as root in failsafe and "mv -R /usr / "?)


Thanks for the help
//Canon