Pocket Magnifier and Light?
You will need a small Phillips head screwdriver like one you would find in a glasses repair kit. With your pocket magnifier laying flat with the LED bulb facing up, pull the magnifier from the top and bottom to reveal the silver/grey middle section. You should see a panel with one screw. Underneath this panel is the battery compartment. You will need 2 CR1130 batteries. Open this compartment and replace the batteries with the + on the left and the – on the right. Replace the cover.