The balancer stands wont really work because they will move around along the axis.
If you have a vice mounted on a bench then pull out the swingarm and clamp it in facing up. Then bolt in the wheel with the axle and spacers. You can either use a dial gauge or a piece of wire / something that will just touch the rim. Then you true until it's straight. Keep in mind it doesn't have to be "perfect" - a little sideways runout is OK.
If you have a vice mounted on a bench then pull out the swingarm and clamp it in facing up. Then bolt in the wheel with the axle and spacers. You can either use a dial gauge or a piece of wire / something that will just touch the rim. Then you true until it's straight. Keep in mind it doesn't have to be "perfect" - a little sideways runout is OK.