To submit an exchange order, select ripple wallet and navigate to exchange tab.
1) select exchange currency pair,
2) key-in the exact spending OR exact receiving amount,
Example: If you key-in the exact spending amount, calculated receiving amount* will be calculated at current exchange rate and will factor-in the fee. Note that exchange rate is real-time and market-based, therefore subject to change.
3) click exchange and confirm.
*Actual receiving amount may deviate from the calculated receiving amount. Calculated receiving amount is the least amount you will receive. If the exchange rate turns in your favour, you will receive more. If it turns against your favour, the order will not be executed.