I wouldn't suggest doing it the way described above because as another person mentioned you may lose your previous bag's contents altogether. (just because it's buggy) Here's how I do it everytime without fail: 1. find backpack just like you find tin cans 2. mouse over backpack 3. select "open bag" 4. left click (once) your bag in your inventory 5. click "open bag" button on the bottom right 6. transfer everything you want from your old bag to the new bag that is still sitting on the floor. Using the arrow keys in the left inventory pane. 7. close out of this inventory screen 8. open your inventory and click on your backpack (that should now be empty) 9. Click the drop button 10. Mouse over the new backpack still sitting on the ground. 11. Select Take backpack. I've noticed that if you try to just take the bag with a current bag on your back there can be problems. This method may take longer at first but you become pretty proficient at doing it quickly, plus it is worth it to NOT lose inventory.
