I would think removing the dash would be a big job and not sure if it is necessary. I have changed out gauges, replaced light bulbs, replaced wiring, added after market pump wiring, worked on the PP all from under the dash. I remove the seat to make it easier but it is still a bit of a pain this way.
I did it this way mostly because I didn't want to risk pulling on or disconnecting all of those wires. There are a ton of them attached to the dash.
2007 XLV Gravity Games
Full Wake Makers upgraded ballast and pumps
1,100 in each rear locker
1,180 in front
OJ 1435 prop, 325 EFI Indmar Assult.
Fresh Air Exhaust
SuckG8
Bunch of other crap