How do I replace egg in a receipe

I am a vegan and replace eggs all the time. It depends on what you are making, but there are a couple ways. There is a product called egg replacer that is made commercially - which is just potato flour. However, if you are baking something you can use 1 tbsp of ground flax seed and mix that with 3 tbsp of water. Mix well. Let sit for about five minutes. It will be a thicker, viscous consistency, much like an egg. This equals one egg in a baked item. You can also do the same with chia seeds. Chia seeds tend to end up looking like poppy seeds though in a baked item. I use the flax seed in all my baked items, including my donuts, my cinnamon rolls and my cakes. If you are trying to make an "eggy" dish, like a quiche, you can use silken tofu. There are a lot of recipe sites, including vegweb and allrecipes which show you how to do this well. I hope this helps.

If you are baking, 1/4 cup of vanilla yogurt per egg is the best substitute I've found. Works best in recipes with 1-2 eggs.

It depends on the recipe. Egg substitution works well for some, not so well for others.

Please elaborate so others here may provide the best advise possible for your particular situation.