How do I edit my ad group bid?

Below are the steps to change your bids on an adgroup -

Navigate to the Ad Groups tab by clicking on PPC Manager in the left hand side menu and clicking on Ad Groups
Click on "Edit" for the ad group you would like to change your bids for
You can enter your new Default Bid in the Adjust AdGroups window. You can also set the "Lock Bid" option so that the bid remains unchanged by the optimizer
Click "Apply Changes" when you are done

You can also make bulk changes by selecting multiple ad groups and clicking on the "Adjust AdGroups" option