According to Apple, it's safe to lay the Mac Pro on its side, so that the case's opening is facing straight up, but I've never found a good reason (or need) to do this. I recommend leaving the Mac Pro standing upright. This puts the hard drive area of the case more or less at eye level. The only disadvantage is that you'll need to hold onto the case when you remove or insert the hard drive sleds, to ensure that the Mac Pro doesn't fall over.
You can use whichever method feels most comfortable for you. All images in this guide will show the Mac Pro standing up.
Remove the Hard Drive Sled
- Ensure that the access latch on the back of the Mac Pro is in the up position. The access latch not only locks the access panel, it also locks the hard drive sleds in place. If the latch isn't up, you won't be able to insert or remove a hard drive sled.
- Pick the hard drive sled you want to use. The sleds are numbered one through four, with the number one sled near the front of the Mac Pro, and the number four sled at the rear. There is no significance to the positions or numbers, except that Apple uses the number one sled as the default location for a hard drive installation.
- Pull the hard drive sled out of the drive bay. This might seem tricky the first time you do it. Just let your fingers curl around the bottom of the sled, and then pull it towards you.