Now let me suggest you a good converter, which I have used and we are regularly using products from same company.
You can download the ost converter from http://www.systoolsgroup.com/ost-recovery.html
I found this tool best among the ost to pst converters available in the market. You can also split your converted pst file and use them as per your need.
For step by step guide you can refer this page http://www.systoolsgroup.com/ost-recovery/how-it-works.html
We have heard great reviews for above converter and it is being highly recommended by many MVP’s too.