Scale down spritesheets without breaking anything else

Hello,

I'm quite new to Unity 2D, and I was wondering, if I can easily replace (or even better: scale down directly) spritesheets (let's say 2048x2048) by a smaller version (1024x1024) without breaking animations, blend trees and such. I tried doing it by hand, but this takes a lot of time, even for a single animation character.

Thanks in advance!

Best regards