You would need somebody with HP Tuners to change the programming if the PCM. Or mail it in to a mail order tune place like PCMofNC or limeswap.com. Either way it will cost at least $100 usd to do it. This will make the PCM completely ignore the security system of the BCM but will still require the 30 minute security relearn.
HOWEVER, this truck, from what we're seeing, is having other issues, either no power to the PCM, BCM and/or IPC or no communication on the network. A tune may not fix your problem. Even if the engine starts, you may wind up with everything else in the truck not working.
There seems to be progress as the IPC is starting to come to life and showing some lights and gauge readings as well as the PRND321 indicator lighting. Before paying for a tune, you should make sure that everything else is working.