I have a 1999 Hot Springs Sovereign with a leak under the moto-massage seat.
Is there any way to remove the side panels so you can replace them or is digging
out the bottom the only way??
I would like to get a plumbing diagram before I start digging.
Thanks in advance.

If the leak is coming from the wood directly behind the moto-jet it is probably the little nipple that has broken. This would be fixed by removing a couple wood slats and digging foam (not much) on the left side of the housing. You will run into a 1/4" hose that attaches to the nipple on the moto housing. It is probably broken. You drill out the old nipple, glue in a new one, add a small piece of 1/4" hose to the old one and attach it to the nipple. Then test the spa with water and if all is OK glue the slats back on.

Hopefully the leak IS from the wood and not from under the base of the spa.

I have the composite skirting instead of wood so I was going to dig from the bottom.
Should I do that or remove the skirting ? Do you know how to remove and replace it ?
Thanks.

The slats are just siliconed and staples from behind. Start at the bottom, use a pry bar and gently pry out the bottom of the 2 slats behind the moto. Go down the verticle side where they come together with a flat bar or strong putty knife and try to go up and down to seperate the boards (they just ship-lap together ). Once the sides are loose you can start to pull out on the two boards from the bottom towards the top and pry them off with your hands.