My Canadian Pension income was in Canadian dollars but it is showing as US$'s on my return. How can I change currency?

You must translate foreign currency into U.S. dollars if you receive income or pay expenses in a foreign currency. In general, use the exchange rate prevailing (i.e., the spot rate) when you receive, pay or accrue the item.  Otherwise, you can choose to use the IRS' Yearly Average Currency Exchange Rates.