Solder a 0.1-Ω resistor on the board at R62. Or, attach a jumper wire between J12 so that it can be used with a current probe.
Measure the voltage across the R62 using an oscilloscope with a differential probe. (For the current probe, coil the wire around the sensor multiple times for good sensitivity).
An ammeter can also be used for this measurement, but the results may be erroneous due to the switching nature of the current.