Replace carbon fuel canister 2006 impala

After removing the fuel filler support on my 2006 Impala SS, I can see the carbon canister mounted on the fender/frame. But how do I get to it to open/test/replace it? I have diagnostic code P0455 which suggests a clogged carbon filter (perhaps due to gasoline getting into it from the the overflow -- I probably filled it too high). I don't see how to get to it without a lot of serious body work removal - obviously not a choice.

Any help appreciated.

Welcome to AF. Remove the inner fender plastic splash shield?