[lithophane lamp]

Hi i have got my lamp stl in cura but i dont know how to reduce the wall thickness please help thankyou 

Terry

[profile to cura]

Hi I am new to 3d printing i have a ender 3 pro, and i have printed a sink strainer for my first print and i want to print another profile from thingiverse and i cannot get the profile into  cura to splice it any info please