No you probably won't hurt anything. I'm going to assume
you've never done this for this post, so don't be insulted
if I say something you already know
1. Electrostatic Discharge (ESD) is bad. Ground yourself
by touching the metal case everytime before you touch any
components inside your PC. Don't wear your bunny slippers
and shuffle your feet across the carpet either.
2. Turn off, unplug.
3. Remember how you take stuff off, perhaps by writing it down.
4. You don't need to unplug either of the 80 giggers.
Typically you have 2 IDE controllers on your motherboard.
You can have 2 drives per controller. Your current setup
is either 2 on 1 or 1 on each. If it's two on one, just
pull the old hard drive from the old pc and bring the cable
that is attached to it to (not the power), plug it into the
2nd controller port and plug in a power supply. DO NOT let
the HD hang in mid air or something crazy. If you're not
mounting it within the PC, you could set it on something
non-conductive like a card board box, but be extremely
careful. Boot up, copy, do whatever you need to.
5. Scenario 2: The 2 80s are on 2 separate cables. I'm
going to give you the easiet way assuming you're not
putting the 60 in there permanantly. Unplug the cable from
one of the 80's. Boot up, if you still boot, you unplugged
the right one. (If not, shut down and switch). Plug the
cable you just pulled into the 60 gig and supply it with
power, follow the precautions in step 4.
Hope that helps. There are many ways to do this, and those
should be the easiest to implement. If you wanted to put
it in permanently, you need to set master/slave options on
the hard drives. Also, if the 2 80's are not on separate
cables, consider putting them on their own--This will
improve performance. Also, if you need more help, ask!
-Regards