[Graphics] Help on inserting Gen 4 OW sprites into Firered

I'm making a Firered hack and one of the things I want to do is replace Red's and Leaf's OW sprites with the fan-made Gen 4 ones, however, I saw that the Gen 4 ones are bigger than the regular ones and can't fit in, anyway I could insert these sprites and expand the OW size safely?

Use 32x32 pixels for Gen 4 OWs, but I prefer not to use them as they look ugly and big on GBA. But it's upto you.

There is a tool on the internet that changes the size of over world sprites. I think it?s called overworld changer.