He's not gonna brick if he follows the guide. The problem with users bricking, and the most common reason for bricking tends to be this: They're on 2.1, and installing A9LH for some reason doesn't work. Maybe they don't have the right file, or maybe they don't know how to troubleshoot their problem.
Instead of coming here to ask for help, they think that straying from the guide is "a good idea" and do just that - They either try updating at 2.1, or they format the device at 2.1. Depending on the console version you have, doing either of these will brick your system. After it's already too late they then come here asking for help
. It's really beyond me why not come here initially instead of messing about with things they don't understand .. I mean it's only your console that's at the risk