The reg is a voltage regulator circuit consisting mainly of a high power switching transistor that is regulated by a variable low voltage trigger , [ yellw wire from CP]. This transistor is encased in epoxy and is non sevicable.

The blower motor can be the cause of reg failure if it is exceeding spec draw [ load amps] I always take a blower motor amp/current reading before changing the reg to verify blower brushes/bearing condition, You are looking for 25 A max @ full speed.
Many reg. failures are due to improper air circulation across the reg. heat sink , usually caused by blocked air filters [ on systems using such]
Pump --No