Here is a picture of a wrench toeing in a brake caliper. You don't need to remove the caliper as this person has done. In fact, that makes the job harder. The picture is useful in that it shows where to put the wrench. Put it either above or below the brake shoe. The caliper in the picture is a side-pull brake.
Here is a picture of a properly toed-in brake. The caliper in this picture is a cantilever. The goal with toeing in is the same for any type of brake.