Yes, making a withdrawal from an ATM is generally the easiest and cheapest way to get cash abroad. Make sure ur ATM got PLUS or Cirrus network, thereby when doing withdrawal from oversea, look for the ATM machine that got PLUS or Cirrus sign. Normally u can found at Airport.
You much activate the service before go aboard, i remember activate through ATM machine will do.
By changing USD here and then change to EURO over will be double charge for u.

Good Luck