Re: volt ohm meter
Yeah the "ohm" meter portion can be used to test continuity, so you'd set it to measure resistance, then touch one probe to a ground such as the exposed output jack on the side of the guitar, and touch the other probe to the two snipped conductor wires, and whichever shows the least resistance (whichever is closest to zero) is the ground wire. The multi meter might even have a "continuity tester" which will simply beep if you touch the two probes to a continuous conductive path, which is even more convenient than looking at the resistance. But... it's a pretty safe bet that the ground lead is a black wire if they're stock pickups.