Power divider input shaft broke? Driveshaft turns, truck does NOT move

Also, the sales person at the drive train company suggested to take out the shaft (with bearings etc) leading to the rear axle, because the bearing may be also be contaminated with metal pieces etc, so we will start with that first and see if we need to replace it.

My question is: the original bolts that were holding down the drop-in differential, had blue thread locker coating applied to them. What is the right way to install the replacement unit? Buy new coated bolts? Coat existing bolts with thread locker?