Magento Question:

In Magento, Currency change is very easy just we need to follow below step:
1) From the Admin panel, select System > Configuration.
2) From the Configuration panel on the left, under General, select the Currency Setup tab.
Click to expand the Currency Options section. Then, do the following:
1) In the Base Currency list, select the primary currency that is used for store transactions.
2) In the Default Display Currency list, select the primary currency that is used to display pricing in your store.
3) In the Allowed Currencies list, select all currencies that are accepted as payment by your store.
When finished, click the Save Config button.