Shower Control Replacement

[ga joe]

Before I go and tear out a wall, or something worse, how do I get into the shower wall to replace the faucet assembly. Mine has a cracked fitting where the shower head hose connects to the body of the valve.  It sprays water when I turn off the shower head .
there are 4 rivet-looking fasteners that hold the assembly to the shower stall wall. Do these just pop out?

Will there be enough slack in the lines to pull the assembly out an inch or so to get to the water lines?

Thanks in advance....

[TripleJ]

Im not sure what your rig has in the way of a shower fixture, but this nifty little panel exposes the back side of my fixture.  This photo is from when I replaced the grey water lines with PEX.

I don't know if the access panel is factory, or if somebody cut it at a later date.  It sure does make it easy to work on stuff...