There are two boards in this ESC
the pics unfortunately don't show the silabs chip... might sit on the back of the blue board
so hard to tell from that what the correct pads are
Do you see the four goldish upright aligned pads on the left bottom corner of the blue board? I would bet that these are the required pads!
(which would make sense since Turnigy also has to flash the chip)
It's not easy to tell which one are which. However, you should be able to determine which of them is connected to GND, and which of them carries VCC (3.3V) (maybe you can follow the traces, or you own a hand multimeter). Once you know which ones are GND and VCC, the other two pads must be C2CK and C2D. So you just could try both possibilities... (mixing up C2CK and C2D won't cause any damage, so just try). I think with a bit checking you have a good chance to figure out the pads whithout having to separate the boards.
With a bit more reasoning we can get further. I checked the pad layouts for the other plushes, and they all have them in row with sequence GND, VCC, C2CK, C2D.
(which makes sense since it's easier for Turnigy to have identical pads layout on all of them)
So, once you know GND you have good change to guess, and identifying GND should be easy by inspection (from the pics I unfrotunately couldn't see)