Most if not all of these tools should be supplied with your Mac mini second drive kit mentioned in Part 1 (they were with the one I bought).
Some heat paste is optional for the additional step. To do this repair you need T6 and T8 Torx screwdrivers, a Mac mini logicboard opener tool, and a small hex (Philips) screwdriver.
But the Mac mini is as tightly assembled as a laptop, and some of the parts and amount of space to work in are pretty small. In comparison to some repairs I have done that involve ungluing things, or seemingly impossible disassembly, this one presents no really complicated challenges. The guide is listed as moderate difficulty, and takes 1-2 hours – that is about right. To do this I followed the iFixit “ Installing Mac mini Late 2012 Dual Hard Drive Kit” Guide. This blog post is the second of three in the series, following Part 1 about the requirements for the server and the choice of hardware.