Hi,
You can try Google search the way to root Sony Xperia M. Each device has difference way to root.
And there is some document about pcap file that you can refer:
http://support.openview.hp.com/selfsolve/document/KM00412329
http://support.openview.hp.com/selfsolve/document/KM1200617
http://support.openview.hp.com/selfsolve/document/KM00592321
I hope it's helpful.
Regards,
Chau