scaling a poster from 24 x 36 to A0 format?

i have an InDesign poster that i prepared at 24" x 36" and i now need to print it and mail it (on deadline) so that it is an A0 format.

i see that this means it now needs to be 33.1" x 46.8". i can see that this means that it needs to be scaled UP by a factor of 1.3 which will leave a little bit more of a border on the short end i think (33.1"/24" = 1.379X and 46.8"/36" = 1.3X).

is there a quick and easy way to do this in InDesign?

THANKS