I wanted to clone an image of the internal hard drive of a new Mac Mini before booting it up. It is common knowledge that a putty knife is the tool to use, as long as it has a thin blade. However, I found a posting to one of Apple’s own forum claiming that a replacement blade for a Kent Marine ProScraper M (part number PROSCLBM) works better. I purchased two of those from the local pet store, but found that they don’t work at all for opening a Mac Mini, as the blade is not long enough. All I accomplished was bending the blades.
I purchased two Hyde #05670 flexible 4″ drywall joint knives, and those worked quite well.
The best instructions I found for removing the hard drive are from Soledad Penadés.