How to close PCM off and then restart Porsche Boxter

[glynna8]

Simple Porsche Boxter 2005. had to dry out the floor after recent storm -- Have several elecrical faults now to rear such as boot release, rear lights on when should be off. How do I drop the PCM which shows as a failure, and then put back on line?
A reset will put all the systems back to normal.