Simple Edit to STL

Hello - I’m brand new here an just found my new addiction.

Sorry for a basic question, but I downloaded stuff from Thingverse and I’m able to slice and print fine. Next I’m trying to do simple things like update my house number on a simple “house number” plate I downloaded.

Can someone please point me in the right direction on how to do that. I’m using Ultimate Cura to slice and I don’t see an option in there. Perhaps I need to use Astroprint but have not figured that out yet.

Thanks for any help!

You can upload your STL to Tinkercad, make the modifications and then export the modified STL to AstroPrint.