To exchange currency, select the portfolio you want to exchange currency in.
Scroll down to the Holdings table, and click on the Cash tab.
Then, click on Exchange.
A box will pop allowing you to exchange currency. You can toggle between converting USD to CAD, or CAD to USD by clicking the top 2 dropdown menus.
Then, input the amount you'd like to exchange, and select "Place Order."
Aaand that's a wrap!