You should use an ATM machine of an international bank such as Citi, HSBC, which are readily available. If you pin is four digits, you may need to add two zeros at the end.

The ATMs of the local banks are reliable in the sense of safety, but some of them may not link to your bank bank at home.

The other thing is that there is usually a very low cap on the amount that can be withdrawn per transaction, at either an international bank or a local bank's ATM. It's generally about the equivalent of USD 300 dollars. The good thing is that this is a cap per use, not per day. So you can slide your card in and out multiple times consecutively. It's just a pain.