Hard Drive/DVD-CD Drive which to install 1st?

I just got a 120gb Hard drive for my MPC2500 and my Teac DVD/CD-RW drive is on its way.
After reading the posts on how to install the DVD drive something i kept noticing was reference to it being more straight forward to install if there is no Hard drive installed.
Will putting the hard drive in now make it harder to install the DVD drive later?

If I remember correctly, the HD will not affect the dvd drive installation. Put the HD in now and install the dvd drive later. You'll be fine.

It's really easy to install the hard drive - back of handbook - and also to take it back out if fitting the CD drive is hampered.
I'd do it.
Kingell