If there are any changes that need to be made to the Will, these will need to be made by way of either a Codicil or by putting a new Will in place. A Codicil is usually used for smaller changes, such as changing who your Executors are. However, fundamental changes are usually better made by putting a new Will in place.
You do not however need to make a new Will if anyone named within it simply changes address. You can leave a note of their new details with your Will to confirm their new address.