You can modify the contents of your cart as long as you haven't finalized your order. Here's a simple guide to making those changes:

Access Your Cart
Click the Bag Icon at the top right corner of your page. 

Adjust Quantities &Item Removal
In your cart, you can change the quantity of an item by clicking the minus (-) or plus (+) signs.
To remove an item completely, simply click the (x) button next to it.

Feel free to explore more options before proceeding by clicking the Continue Shopping button to move forward.