how to change to power cord on my black & decker H 552 400 Watt 10mm(3/8") ?

There are several things you can do to achieve this.

Dismantle the drill (just two shell halves) and fit a new cable complete with US style plug - or fit a new cable with no plug and fit the plug of your choice.

Just cut the existing 13A (presumably) plug from your existing cable and fit a NEMA (USA) style plug - Amazon have them in several styles.

Leave the cable exactly as it is and just buy an adapter that converts a 13A plug and allows it to be used in an American style NEMA outlet.

Be aware that European power and US power are not the same - is your drill dual voltage? Does it matter? Are you aware of the likely current implications on 115V?

Me? I'd just buy a travel adapter for £1.

Peccavi
May 2013