Summarize the following:
Your foal will be more comfortable being weaned in an environment that it is familiar with. About 3 to 4 days before you wean your foal, move it and its mother into a large pen. Keep them in this pen as much as possible, only moving them inside to sleep if need be. It's best to wean 2 or more foals at the same time, so the foals can keep each other company as they are weaned. Remove 1 mare from its foal at a time, waiting at least 1 day before removing the next mare. This will prevent your foals from panicking at the same time and stressing each other further. Once the foal has adjusted to the pen, lead its mother to a new pen or stable far away. Make sure that they cannot hear or see each other, otherwise, the foal will attempt to find its mother and may end up hurting itself. It may help to feed your foal with some hay or creep feed while you move its mother to a different pen. This will keep it distracted and may stop it from panicking as much once it realises it is being weaned. Each foal will respond to being weaned differently. Some may panic for only a few minutes, where others may take up to a day to calm down. Watch your foal to make sure it cannot escape from the pen or hurt itself on the fence. Feed it as you normally would and allow it to calm down naturally before introducing its companion to the pen. Check the edge of the fence for loose nails or anything else that could hurt your foal before weaning it. It will likely spend a lot of time near the edges of the pen trying to find its mother. Once the mother and foal have been separated from each other, it will take around 1 month for the mother to stop lactating and the foal to adjust to being on its own. Give both horses plenty of time to adjust to their new living style before reintroducing them. If you bring the mother and the foal back together before the foal has been properly weaned, you'll just need to wean them again. Make sure the mother has stopped lactating and the foal has adjusted to being apart from its mother before reintroducing them.

Summary:
Leave your mare and foal in a field for 3 to 4 days. Take the mare out of sight and earshot of the foal. Give the foal time to calm down before introducing its friend or nanny. Keep the mare and foal separate for around 1 month.