Is there a way to take the tiles from Pokemon Ruby and using them in Fire Red and Leaf Green?

That tutorial is useless for him.
Mega-Byte, there is a program that comes with elite map, called UNLZ-GBA, it will allow you to look for compressed tiles in the pokemon games, you will have to go though the rom with the program, edit those, and then re-import.

You could do it the lazy way with advance-map's tile export+import function, however that eats up a bit of free space with each use, so it is up to you.