Yogurt you can do whatever way works. You can give each part of a spoon full individually. That way you know they all got some. Honestly I use a spoon or even a dropper and just squidge a little bit in their mouth in the side (not down the throat) so they have to tongue it back and they won't choke on it. it's the right thickness for that. Dosage isn't exact - somewhere between 1 teaspoon to four tablespoons per bird. It won't hurt them unless they eat just tons of yogurt.
That way you're also examining each of them for other things - weight, etc, to make sure they're doing good. It's a great once a month way of keeping tabs on weights, etc, to prevent illness.
You can also try making a mash. Take up their food at night. In the morning, mix a batch of crumbles, yogurt, some mashed egg yolks if you feel like it, and water. Mix it quickly to get the yogurt in all of it. Then let it sit until it's as dry or wet as it's going to be - about five minutes. Then set that out there and make sure each bird gets some. Then clean the pans and put out their usual food. Have a good sit and watch them, see who gets bullied out of eating. You can even use a black sharpie pen to put a dot or line on top of the bullied ones so that when you need to check them later, you can find the ones whose weight you want to monitor more quickly and not have to pick each bird up. The dots go away and you can't see them so they're not ugly.
I found out that tip by accident as one of my newest chicks had a dot on her head from the hatchery. It really helped me pick her out, and thus the dotted head was born. /wink
Since your birds have access to woods, I'd definitely have a twice a year worming program in place. If you buy ivermectin, buy generic drop-on. It only takes a couple of drops - talk to us when you get it and we'll give you a dosage. You can even see if you can talk to neighbors or friends about going in with them on some.
Also, ivermectin for the water is available online at some pigeon suppliers. It's less expensive than the drop on (unless you go generic). The reason I like the spot-on again is it allows me to monitor my flock and catch light-weights before they become sick and possibly make the rest of the flock sick.
Prevention is my biggest money saver.
Cheers!