+1 on these steps - I had to take my time, especially during the re-assembly - and when things are positioned right they tend to "snap" into place, which is great feedback that the part or cable was connected properly. I also did not let the lack of the logic board removal tool stop me - I used 2 small screwdrivers that fit nicely into the holes for the tool, and the leverage points inside the holes are easy to find. Used this guide to replace a hard drive with an SSD in my Mac Mini Mid-2010 pulled from a dumpster of a company that was moving - and it is a nice file server for my home network to this day.