With an exit update version 0.1.1203.6028 you no longer need to replace the game file. Any save can be put into “Creative Mode”
The “worldsettings.xml” file should appear in your save folder. You just need to open it in a text editor and find the line:
And save the changes.
This should work even after updating the game.
P.S. Default save folder
% USERPROFILE% \ Documents \ My Games \ Stationeers \ saves \ save name \ worldsettings.xml