How do I separate lines of a score into separate instrument partitions?

I play in a lot of quartets and quintets. While we find scores of music, is there a way to take a music score (in a pdf format?), convert it (which I have done), open it in Musescore, and then have the software separate the four or five lines into a partition for Violin 1, Violin 2, Alto, Cello, etc...? Someone told me that this is possible, but I cannot seem to figure it out. Any help would be appreciated.

Thanks,
JRo