REplacing Copper in tub/shower HELP!!

[Sunny51]

Hey folks,
I posted this question yesterday but may have put it in obscure place.


76' 31' rear Sovereign:
We are in the middle of repalcing copper with Pex/Sharkbite.
Curbside is done!!! YEA!!!
yesterdays test revealed water flowing out from between tub and shower i nfar corner.

How do I get to the copper for shower and tub?
Can I (PLEASE!) get to it without taking tub out?

I hope someone has a sure fire way to get in there!!!
Pic included for clarity.

MAny thanks ahead of time...
Sunny