Brakes, leaks, mekanik

I tried to replace my front brake pads on my 2006 E/CLS 320 CDI with a friend's help. He (quote is important) "knows what he is doing"; he made me unbolt not the bolts that hold the caliper to the car, but the bolts that hold the caliper to the other part of the caliper.
In the end I got a torrent of brake fluid, I put the bolts back in the holes and the trust I had for him back in my pocket. It stopped leaking. It doesn't seem like I tore anything apart, which is a good thing. Moreover, the car has SBC. Which he forgot (and I didn't knew) to deactivate. And he made me do the work so "I'll know how to do it next time".
Anyways, everything is put back in place, I still got my fingers so we're good, and I watched the first Youtube video I saw which explained how to do it, correctly this time.
I have one question: is it safe to bring the car to an auto shop to do the brake fluid change not doing more than 20kmh and braking with the parking brake (my house is a bit uphill with a roundabout right down)? (it has lost quite a bit of fluid and I am afraid air may have got in).
TL,DR: Can I brake down a small hill with the parking brake, will the engine brake be enough, can I get the transmission to stay in 1st or 2nd gear to keep the speed down?

Where is the SBC plug located?




http://www.cardiagnostics.be/-now/DA...n/W211-SBC.pdf
-Page 29 describes what happens when you unplug or deactivate the SBC so...yes, you can bleed the front brake caliper that has air in it. Unplugging the SBC will throw a "current" code while unplugged and a "stored" code after plugging back into the harness.
-Page 39 tells you what will activate the system while you have it apart. You do not want to activate the system until ready to put back into service. Until then, deactivate with STAR or unplug the SBC module.
-Page 42 explains why you would prefer to use STAR to deactivate.
-Page 43 explains when SBC must be deactivated for work to be performed.
-Page 45 explains why you would prefer to reactivate SBC with STAR.
There are 68 pages of goodness in this technical information.




http://www.cardiagnostics.be/-now/DA...n/W211-SBC.pdf
-Page 29 describes what happens when you unplug or deactivate the SBC so...yes, you can bleed the front brake caliper that has air in it. Unplugging the SBC will throw a "current" code while unplugged and a "stored" code after plugging back into the harness.
-Page 39 tells you what will activate the system while you have it apart. You do not want to activate the system until ready to put back into service. Until then, deactivate with STAR or unplug the SBC module.
-Page 42 explains why you would prefer to use STAR to deactivate.
-Page 43 explains when SBC must be deactivated for work to be performed.
-Page 45 explains why you would prefer to reactivate SBC with STAR.
There are 68 pages of goodness in this technical information.



