Question -> shrinking non-root lvms, then grow root "/" lvm

I have two systems I recently loaded with RHEL 6.5 server. I realized afterwards, I did not provide enough space to the "/" file system, it's currently at 90% usage. I typically never run into this problem; I have to date never had to shrink/grow any LVM except in class because I have (until now) properly measured my disks, measuring twice, cutting once... So on the Windshield-Bug spectrum, I'm currently the bug in this round.

I found three other LVM file systems I could reduce:
/dev/mapper/disk0-tmp "/tmp" reduce by 8gb
/dev/mapper/disk0-var "/var' reduce by 4gb
/var/mapper/disk0-spool "/var/spool" reduce by 4gb
/dev/mapper/disk0-log "/var/log" reduce by 4gb
/dev/mapper/disk0-home "/home" reduce by 8gb

This would reclaim 28GB that I would want to allocate to /dev/mapper/disk0-slash "/"

I found the documentation to shrink the LVMs above at this link

I found the documentation to grow the LVM "/" at this link

And the last link I posted said if I make room elsewhere, I do not have to add a physical volume, but just use the unused space that I created as a result of shrinking the other volumes.

MY QUESTION:
When I grow the "/" LVM, do I have to do that in the single user mode since the system is using "/"
Can I grow the lvm /dev/mapper/disk0-slash while in run level 3? Are there any other steps I should take when growing the LVM for "/"?

Request help please...

Thanks