HotSpring Vanguard Repair Advice?

[Doctauri]

I have a 2005 HotSpring Vanguard that developed a small leak.  I called the [semi]local repair company out.  First he complained that it wasn't a Jetsetter (which we previously had, but apparently their records weren't updated), and was too heavy for him to move around to easily access.

So, he took off a panel near where we saw water, and found that termites had eaten the frame.  He went on how it was the worst infestation he'd ever seen, and so on.  However he'd only pulled off one set of panels (about 18", from top to bottom).  He stopped there, said it was probably not worth it, and that to repair the damage would be between $2500 and $3000.  He then went on to tell me that he'd make me a good deal on a floor model if I wanted.  That was back on November 30.

So, I resolved myself to needing a new spa and went searching.  Found a good deal, and was ready to order.  Today, I moved the old Vanguard out to clean up and make an electrical change, when I decided to pull the rest of the panels off on that side.

So there's no doubt, the termites have eaten the frame on one end, however, once you get to the corners, the wood is untouched.  I'm thinking the repair is not nearly as bad as the service tech made it out.  I'm not sure if he was just trying to push a sale, or what, but I think I'm going to try to repair it.

So I have a couple of question:
1) In removing the old half eaten wood, it appears that the panels are meant to pop on/off or slide in/out (think push into place then slide to the right).  The fact that the panels can be purchased as an entire piece tends to support this (http://www.backyardplus.com/proddetail.php?prod=W73012).  Can someone tell me how to remove the panels? 

2) It appears that the frame is more to give the panels something to attach to than structural, is this true?

3) Once I've pulled out the destroyed foam and rebuilt the frame (and fixed the leak), what do I use to replace the foam insulation?  Spray foam looks to be ridiculously expensive, I'm sure because the minimum quantity is much more than I need.  Is there some alternative?  What about filling the void with regular attic insulation then foam panels in the spaces of the frame?

Thanks for any help!

[BullFrogSpasMN]

the only thing that worries me is the leak...very rarely is it just "1 tiny leak" more often its 2 or 3 or 4 small leaks, are you 100% sure there is only 1 leak in-foam?  The reason I say this is because you can go through pulling panels, repairing frame pieces, installing new panels, spraying foam into it, etc etc. and you could still find yourself having a leak which makes all your repairs for nothing...just something to think about

[Doctauri]

Yea, I have no idea to be honest.  I figure I'd pull the panels, pull out the insulation that I know was wet, then fill it and see what's what.

There's a very good chance that I'll regret this decision, however, at least I'll know I did everything I could before laying out the money to buy a new one.

Thanks ;-)