How can I repair anvils?
Solution 1:
You cannot repair an Anvil. The Anvil will break if it's done. You can just build another one and place it on the old place of the Anvil.
You just can repair Items at the Anvil. This is the thing you see in the release logs called "Anvil repairing has been rebalanced" as it was way too expensive in older versions.
Solution 2:
You cannot repair an Anvil, even using another one.
The main change of version 1.8 is about the prior work penalty.