Dont now if it is correct way. But i did it by doing this:
open ThemeChanger and select JLD (jolla love day theme updated to jolla theme 2.0)
Then delete sailfish 003 theme and reboot n9
then install sailfish 003 theme
then open fileboxroot en go to usr/share/themes/jld/meegotouch/icons and select and copy all items in there to usr/share/themes/sailfish/meegotouch/icons
then i go back to ThemeChanger en select sailfish theme and then reboot n9
that did it for me.