saving/ SW 2013 as 2012

hi, i've just got solidworks 2013 and have happily made a few parts and assemblies, but have just realised my University still uses 2012!

are there ways of either converting my assemblies to the 2012 version,

opening them as 2012 at University,

running the 2012 program through the 2013 version

or saving future files to 2012? - MS word has an option to save as previous versions of the program? (e.g. Word 97-2003 Document)

i am aware that SW 2012 SP.5 should open parts/assemblies but i assume the University ahas an earlier version than this...

any help will be much apprciated

thanks

SolidworksGeneral