I recently needed to removed the drive from a Western Digital My Book External USB/eSATA drive enclosure. Unfortunately, this wasn't an obvious process and this excellent article by Scott Cramer didn't apply to the newer version (1 TB drive) enclosure I have. So here you go, the steps required to disassemble a new-style Western Digital My Book drive enclosure.
1. Locate the two rubber pads on the bottom of the enclosure near the front, curved surface. Remove these two pads. Depress the two tabs below using a small flat-head screwdriver.
1a. With a couple of credit cards, pry the back edge of the casing apart and hold them open with the credit cards. There are some locking mechanisms there that need to be held apart. You can now slide the plastic casings apart.
2. Slide the clear plastic LED front panel conduit forward and remove.
3. Rotate the hard drive/carrier assembly sideways and then lift away from the case
4. Remove the two screws holding the metal connector casing. Slide it upwards and remove it
5. Slide the circuit board upwards (away from the drive), just like you did for the metal casing.
6. Remove the 4 screws holding the hard drive to the metal carrier. You'll see that it is a standard 3.5" desktop SATA drive.
You're done!
Repeat the steps in reverse order to re-assemble the enclosure.
Getting Your Data Off of the Drive
In most cases, the circuit board inside the enclosure is the cause of the failure and the drive itself is fine. The drive is a standard 3.5-inch SATA drive and easiest way to get your data off is to use a SATA-to-USB adapter dock, such as this Thermaltake Dock at Amazon.com.
Thermaltake BlacX eSATA USB Docking Station
To Install a Different SATA Drive in the Enclosure:
In most cases, the enclosure is probably what is failed. But if you're sure it is working, you can replace the original drive with a different drive. For example, I replaced the 1TB drive with a 200GB drive. I didn't have to do anything special, I just put the new drive in the enclosure, plugged everything in, and it worked.
However, a few people have had with the enclosure recognizing the new drive. If you do, try this:
(thanks Fisslefink) The onboard chipset memory of the MyBook Studio needed to be reset. When you remove the metal shielding, you see the circuit board and all of the different components. One of them is two metal prongs, an empty jumper (J6, may be different on your board), sticking out of the circuit board, near the DC power input. By shorting those jumper pins together with a metal screwdriver for 2 seconds (with the drive OFF and the power cord REMOVED!), the board will reset so it can recognize the new drive.
For what it's worth, if your drive supports slower SATA operation, you can use a traditional jumper shunt (those darn little black things that get lost all the time!) to connect the jumpers at OPT1 on the 250GB drive itself. This switches it from the faster "SATA 2" 3.0GB/s transfer rate to the slower 1.5GB/s rate, with which the enclosure chipset may be more compatible.
If you are looking for an even more robust backup solution, I recommend an online (offsite) backup service in addition to an external drive: Mozy Unlimited Online (offsite) Backup – $4.95/Month

HI,
I have the 500gig mybook pro. stopped mounting on my G5 mac. I need to retrieve what was on my backup, and am nervous about taking it out of the case, and putting it in the mac internally. What would you suggest as the safest thing to try first. It's not the power, I tried both firewire & usb. It will power up, spin, it shows in disc utility, just won't mount.
You have nothing to lose by remove it from the case and attaching it directly. You could try a disc recovery utility, but I wouldn't do that until you've ruled out a failure of the external enclosure.
I bought the Thermaltake BlacX eSATA USB Docking Station. Will be here Friday. Hope to God it works! What is the best backup external hard drive out there. I'll be getting two! It has to be MAC compatible.
The best external drive for backup is one that has 2 mirrored (i.e. RAID 1) drives inside the enclosure. So if it has two 1-terabyte drives, you only have 1 TB of storage space, but the unit keeps on working, and all data is accessible, even if one of the drives fails.
For automatic in-home backup, I use a Windows Home Server. The HP servers have software that allows them to works as MAC Time Capsules (in addition to working with Windows PCs.) Also, Windows Home Server supports redundant drives.
The best back solution is one that is automatic, and off-site (in case of a catastrophic event.) I recommend using Mozy.com for automatic offsite backup. Unlimited storage costs $60/year.