Not only do i have a tutorial on it, but for my own convenience i made an entire pack of them,
http://ra2.savagewar.co.uk/pafiledb/...on=file&id=237
Contains everything except the squid and the dinosaurs because they should be big (that includes death animations, infantry, animals). Enjoy. If the files you want resizing are not RA2 or YR infantry from the game itself, zip them up and email them to
tratos@savagewar.co.uk with a return address and i'll resize them and send them back.