How to replace Finder
Find Finder.app on the OSBoot partition. Its in System/Library/CoreServices.
Rename Finder.app to Finder.app.sav. Copy in your replacement app and rename it to Finder.app.
mv Finder.app Finder.app.sav cp /<some-path>/CenteraStage.app Finder.app
Now, navigate into its Contents/MacOS folder and copy its bin to Finder.
cd Contents/MacOS cp CenterStage Finder