How can I import stuff from Creo Element Direct Modelling Express 4 in Creo 2.0

Hi ! I would like to import the old project I did (pk2 files) into Creo 2.0 because I don't want to loose all the work I did.
I would like to know if it's possible to do it .
If yes, how can I do that ???

Thank you a lot for your help !!!!