Cutting a section of the plastic pan for access is a common approach for some repairs. You just have to be careful not to nick the tank or pipes in the process. My 2002 25 had that done to it, and a piece of aluminum screwed in over the hole as a cover.
"You cannot reason someone out of a position they have not been reasoned into"
Al, K5TAN and Missy, N4RGO
2002 Classic 30 Slideout
2001 Safari 25 RB Twin (Gone, but not forgotten)
2013 Dodge 2500 Laramie 4x4 Megacab Cummins
WBCCI 1322, TAC FL-39, AIR 82265