transistor equivalents

[jaspervlb]

Thank you for the awesome project.
I am quickly trying to build the pcb, however I have no bc858B nor bc848C readily available.

I figured the BC858B for the master interface is working in saturated mode and is thus easily replaced by a similar transistor (I used S9012.

As the slave interface drives the current I am unsure about replacing those. Can you help me out in understanding how that circuit works and the function of each transistor? Looking at the bare specs I would replace the BC858B with 2N3906 (but the hfe seems quite off maybe S9015 is better?). The BC848C I would replace with 2N3904 but again the hfe is off, so maybe I better use S9014. If I replace the transistors should I change some of the resistors as well?