The Butler’s Friend (also known as the Ah-So cork remover or cork puller) removes any cork without damaging it. It makes a great alternative to using a corkscrew, especially if the cork is old, crumbling, or even a little broken. It does not work too well on composite corks found in cheaper wines.
This nifty device has two prongs, one longer than the other. First insert the longer prong between the bottle and cork. Then continue with the second prong and, rocking the handle slowly side-to-side, slide both prongs down until the top of the gadget touches the cork. Once both prongs are gripping the cork, use a twisting motion to pull the sturdy handle up and slide the cork from the bottle. You will find the cork comes out surprisingly easily. This video of halfwine.com's founder Kevin demonstrates the above, and also how you use it to replace the cork: click here.
The Butler’s Friend is also known as the Butler’s Thief. The idea is that the dishonest butler can use this tool to carefully remove the cork from a good bottle of wine. He then replaces the good wine with a cheaper substitute and re-inserts the cork and the Lord of the Manor is none the wiser! However as all watchers of Downton Abbey will know, the butler is responsible for choosing a good bottle of wine and he uses his Friend to open a bottle from a shipment to test how the wine is progressing and when it will be ready for drinking.
If you want to read an amusing article about all the different types of ways to open a bottle please click How NOT to Open Wine Like an Ah-So.