1 - Be sure to confirm you are visiting the official META Exchange website

2 - Once you have successfully placed a limit order on the exchange, on the top right you will find a box where it says cancel all orders

3 - Then click on the yellow box that says confirm

4 - You have now cancelled your open order.

5 - You can also close your open order by clicking on dashboard

6 - Then click on open orders and click where it says cancel all open orders or you can also close your open orders individually by clicking where it says cancel.