All Sibelius files have been saved in the current Sibelius 7 format.
To open in an earlier version of this program or into another music software program, use the MIDI file and import this into your version. You should be able to open this and then save it in the format you have installed. Once this has been done, the score can be edited to the size and format you require.
Please note that Rehearsal letters and performance detail will not have transferred but bar numbers should have been added.
Dynamics and articulation can be heard on the mp3 recording.