First: I APPROVE OF YOUR CHOICE.. I got my Motor home in 2005, it came with a PD 9180+ Wizard (the 9200 is identical to the 9100 but has the Wiz built in, mine is plugged in)
I've been trying to find a better one ever since. Can't do it, there is no better one for flooded wet cells. A few as good but none better.
Now: How to "UPGRADE" to the 9200
Find the wire that goes from teh circuit breaker to the CONVERTER portion of yout 6300.. Remove it from the breaker, use teh same breaker to power the 9200 and hook it to either the house side of the battery disconnect or batteries direct.
Method 2: Progressive Dynamics 4600 (Cheaper I think)
Remove the 6300 being sure to label all wires Remove the "Guts" (the electronics behind the fuse/breaker panel) and sell to scrap yard.
Replce GUTS with 4600.. You may wish to add a jumper or the blue and red wires from the existing "Guts" connect together to the 4600
Videos and other instructrions on the left frame at bestconverters dot com (not sure about the S which is why I speled out DOT Either converter or converters Delete spaces of course.)