To change your backer level, simply log into kickstarter, go to the Low Tech Laboratory page and click, "Manage My Pledge"
There should be a box with the backer level you chose. Here you will click on the button that says "Change Your Pledge"
The backer level you are currently at will be noted.
To change the backer level, scroll to the level you wish to change to. Click on it.
Be sure to click on "Change Pledge"
A confirmation screen will pop up. Now click on "Confirm Changes"
If you wish to keep your backer level, but change the amount you have backed, Follow these steps:
To change your backer amount, simply log into kickstarter, go to the Low Tech Laboratory page and click, "Manage My Pledge"
There should be a box with the backer level you chose. Here you will click on the button that says "Change Your Pledge"
in the text box next the the button, you will enter how much you want to ADD to your pledge. The amount you put into this box will not replace the amount you have already backed, but ADD it to your current pledge.
Once you have typed the amount you want to ADD to your backer level, the total amount will appear in the button. Now you want to click it.
You will come to a confirmation screen. If you do not hit "Confirm Changes", your new pledge amount will not be saved.