Defining and adding relation to STEP File

Hi,

I just got a STEP file of PCB made in Altium and they want me to convert it into Drawing. I've imported it into SW2013 no problem and saved it as Part. That is all nice but when I open up the sketch nothing is defined and I have a trouble defining it. I cannot add relations, I cannot measure diameters nor lines, I cannot do nothing.

Anybody had similar experience or I am just trying to do something that is impossible?

SolidworksSketching