That is some significant damage!! Did you have any exterior skin damage?
In answer to your initial question, it appears you would have to replace the wheel wells from inside from what I've seen and understand about the basic construction of the AS.
If you don't have insurance and undertake the repair yourself, I'm sure this community will support you with whatever information you need. Best of luck.
Lew TAC #WI-6
Nobody can help everybody, but everybody can help somebody.