[header] How to open a computer [title] Gather your tools. [step] Most cases will just one screwdriver to access. Some cases use thumbscrews, but a screwdriver can still help loosen an overly-tight screw. 
[substeps] The most common screw is a 6-32, which you can use a standard 2 phillips screwdriver to remove. This is the larger of the two most common sizes.