IBM desktop computers have a Type, and Model Number.
It's usually on the back of the computer case located near the Windows Product Key.
Example: IBM M Pro 6219 10F.
6219 is the Type, 10F is the Model Number.
Since I don't know, I'm going to base it on an IBM M Pro 6219.
If this information is incorrect, simply state the correct Type in a Comment.
Facing the computer, your left side is the left side of the computer. The left side is the Side Cover, that removes. There is a Release Latch.
It's approximately in the middle coming up from the bottom, and almost halfway across the side cover.
The latch pivots. The front of the latch faces the front of the computer. It resembles a flip tab.
Insert a finger tip under the front of the latch, gently pull to the outside. This releases the side cover.
Slide the side cover towards the rear of the computer, lift it up, and out, then set it aside.
If you wish, you can give me all of the number/letters, (Manufacturers Code), that you see on the harddrive, and I'll tell you exactly what you're looking at.
The Hardware Maintenance Manual I'm looking at, states that it could be either an IDE, (PATA), or SCSI harddrive.
Doesn't state the different sizes offered, spindle speed, Seek Time, or any other information.
This is IBM Support, and the download page for the Hardware Maintenance Manual, for the IBM M Pro 6219 series,http://www-947.ibm.com/systems/support/supportsite.wss/docdisplay?lndocid=MIGR-45692&brandind=5000004
On this page scroll down with your eyes to the heading - File link
Directly under File link is the file name - 71p9918.pdf
Left-click on it.
This is a PDF file download. You may not see anything happening for up to 30 seconds after you click on the link.
It took 22 seconds before I saw the first page, and the file was also fully downloaded. I use a medium speed DSL connection.
I don't know if you are familiar with PDF files. If so, please disregard the following.
At the top header of the PDF file is a Page Number box.
It is to the right of the blue Down Arrow.
Put your mouse cursor in the box. Left-click once. Type 51
Press the Enter key.
Page 51 shows you, and tells you how to remove the side cover.