Risky especially in SFO. But there is no airside way to transit from one side of the international terminal to the other; it's built kind of like an airplane, with the center (fuselage) serving as check-in and the two wings branching off. You'll need to exit one side, check-in, then cross to the other and go through security again. Easily doable if your inbound is on schedule.

OLCI will be your friend here, assuming it works.