In the case of the last screw 379 it is also for a specialist impossible to work properly;
simply because Ming cycle was unable until today to supply a recommended torque! 
Even workstores do not have any additional information besides the official, there is no dedicated workshop manual existent as far as I know (at least not in English - possibly in Chinese…)
Especially for that little bolt I wrote that a while ago:
Tips from Mark.pdf torque warning!
Regarding torque key; I like to work with these tools and have a few of different torque ranges here naturally. But on this single bolt I’d recommend NOT to use them because:
- They are mostly not precise at the lowest end of the range.
- The “click” of very low torques can be pretty silent; there’s a certain risk to miss it.
I’d use a common, 90° angled Allen key but vice-versa - meaning to use the longer leg inserted into the bolt’s head - and then drive the shorter leg between thumb and forefinger, and that’s it.
Btw, taking the rear wheel off means also to disassemble the parts goup around/below the counterpart of the magnet - at this point in time you should check also part 338 (called magnet spacer) if it is bent or broken; it should look symmetrical. Please replace if necessary.
Ah, some more:
It can’t be guaranteed that the brake discs (rotors) are in exactly the same position like that of your old wheels. So, if you remount your calipers, be sure first that the brake pads are out of the way of the rotors before starting to mount the two bolts. In most cases you have to re-adjust the pads anyway.
You know how to tighten the caliper bolts of disc brakes?
- Tighten the bolts - but not fully yet.
- Pull the brake lever (caliper should find optimal position by its own).
- Now tighten fully.
- Let the lever go.
(Before this action it is necessary to adjust the pads “about” right.)