documentation is on that site as well. suggest reading through it all before you mess with updating.
now for flashing the tunes, you just plug your adrenaline module into the computer. If your pulse monitor already has custom tuning unlocked then I would just leave it alone and not bother updating it.
and I take it you have a pulse v1 and pushing the goofy little rubber buttons isn't working anymore to change power levels? If so there is a fix for that if you think you can handle some minor trimming, grinding, and soldering. it's nothing complicated, just takes about an hour to do...
you basically open up the monitor, solder in tactile switches to bypass the stupid touch contacts, and then you grind down the button guides inside the back of the plastic cover enough to clear the tactile switches, then trim the buttons shorter as they are going to be sticking out a lot further. Once that is done, no more bad buttons! they'll work each and every time!
Pulse Monitor Modification (no more bad buttons!) - Midwest Diesel Connection
link shows the process with pictures of how to perform the mod...you can also search cumminsforum, there are a couple threads on it there as well...same process all around though.
I did this to my pulse monitor years ago and haven't had a button issue since.
now if you have a PV2, then that is a different story..but I haven't heard of PV2's having a bad button issue...