You can exchange currencies very easily. All you need to do is log in to the mobile application.
Go to the "Wallet" tab. Then click on the currency you want to exchange. Click on the 
icon. To make an exchange - enter the amount and select the currency and confirm it by clicking "Exchange". Confirm the exchange with your application code.
Remember! Not all the currency pairs are exchangeable. If a pair you look for is not available, try exchanging to EUR or USD first and then to your desired currency.