To cancel your open cover order,

1. Go to the order book by clicking on orders from the bottom menu

2. Under open orders, click on the order you want to cancel. You can cancel the order only if the buy/sell order leg has not been executed. Your order will remain under open orders until both legs (buy/sell 
and stoploss) of the order are executed

3. In the buy/sell order tab, click on the cancel button and click on yes to confirm the cancellation