Being a Computer Programmer/Consultant I had to learn to Think about Contingency Planning which has helped me in a lot of situations because what you expect to happen usually doesn't happen and you have to take an alternate course of action.
A good mantra.
I think the overall lesson with this practice is to take your time, plan you moves, have the right tools, and execute the steps carefully.
One thing that continues to amaze me is the number of folks doing this, as there are not that many owned
devices out in the field (99% leased), and of course, opening up a unit violates the warranty - which may result in the end user having to pay full retail some time in the future for the device if it ever needs service, replacement, or it has to be returned.
I know that gets repeated, but it is a risk that alot of folks don't realize until its too late.