I have downloaded Materials selector, from extensions warehouse. It shows up on my extensions manager but for the life of me i cant get it into sketchup!
It’s loading in SketchUp already !
However you also need TT_Lib… installing…
AND Material Replacer appears under an entry in the SketchUp > Tools menu…
Activate it there…
Read up on its usage in the More Info link in its entry in the SketchUcation PluginStore… [or EW ?]