I have a Maxtor Basics 3200 external hard drive. I bought it about three years ago and it has given reliable service ever since. There was no need to pull it apart, save for curiosity. StevenJ had trouble with something similar back along, and I thought I'd take a peep inside the casing to see what's in there.
My Maxtor 3200 has a 320GB capacity and is roughly the size of two DVD movie cases, mounted on a small plastic plinth which detaches easily.
The case is a clam-shell arrangement. In order to open it, it is necessary to remove the two screws adjacent to the power and USB sockets. Then the two halves can be prised apart with a small flat screwdriver. This requires care: it is best to start at the end where the sockets are located and work towards the front where the LED power indicator is situated.
Notice that the lugs and the eyes that receive them, the means by which the two halves are held together, are located between the air vents.
Once the casing has been opened, one is presented with a perforated metal box, which appears to act as a Faraday cage, protecting the innards from electrical interference.
This is held loosely within the casing by four translucent rubber spacers and the whole is easily removed as it is not secured.
Remove the four screws from the cage and carefully peel back the woven-metal tape and small strips that secure the cable that communicates with the LED power indicator. The cage will then slide apart in two pieces, exposing a conventional hard disk drive and PCB on which is mounted the sockets for power and data.
Remove the three screws securing the PCB and the whole assembly will detach from the cage with ease.
The PCB can be detached from the hard disk drive simply by unplugging the power and data connection. The hard disk drive in this instance is a 320GB Seagate IDE unit.
Refitting is the reverse of removal (with apologies to Haynes).