How difficult is it to read and modify .STEP files. I have a .STEP file of a connector that I would like to modify for different pin counts. I've looked at several applications that claim they can import and edit .STEP files, but so far I haven't been able to get one to even open the file! I know the file is good, I can view it in a .STP viewer.
Is it possible to modify these or am I living the impossible dream?