1) First, buy a new battery with toolset, unless you already have a set of watchmaker tools that includes both Phillips head screwdrivers and tiny Torx drivers. I bought the tools myself, with a Nook Color battery. Since then I have used them to replace two additional batteries in two Nook HD+ tablets. Make sure you order a battery for a model BNTV600 (the Nook HD+ with 8.9" screen). Two sources: Barnes & Noble Nook HD+ Repair and Barnes & Noble 2) Follow these instructions to replace the battery: 3) Charge the new battery for 2+ hours before starting the Nook HD+, or 5+ hours for a full charge. 4) Dispose of the old lithium battery as hazardous waste via a recycling center.