This guide shows you how to change the magnifier glass in Slingshot. This example uses (e)papirus icon theme as demostration and it uses the good old elementary logo for the purpose. If you are skilled with inkscape you can make your own.
If you’re using a different icon theme, you need to adjust this guide.
First download the “e” from here: Download
Extract it. When it’s done copy it to ~/.icons/ePapirus/symbolic/actions
Tested on: elementary OS 5.1.4