Here it is again anyway:
Assuming you mean "cargo container":Make sure you're in the same room as it.Click the "Items" button.Scroll down if necessary until you can see the cargo container.Next to its picture, you should see a drop-down box with the number of items in it. Select the amount of items you want to remove, then click the "remove" button.If it's a different form of storage item such as a backpack or trunk:Click the "Items" button.Scroll down if necessary until you can see the backpack/trunk/whatever your item is stored in.Next to its picture, you should see a button called "view contents". Click it and find your item.Click the "drop" button next to your item.In either case, you item will now be on the floor.
It's also possible you're looking at the item in your inventory, and you're not actually at your item's location. n that case there's nothing you can do, since you can remotely remove an items from a container.