Changing a battery in your watch is a simple process. If done properly, it should take less than five minutes with very minimal costs.
Protect the watch face by laying the watch on a cloth or other soft material before beginning. Oftentimes, Relic watches come with a soft cloth for cleaning the face. Use this cloth during this step.
Remove the back of the watch. Either use the specified watch-back remover or a pair of pliers by adjusting it the to the correct width of the watch back and spinning it off, or use the flathead screwdriver to pop the back off, depending on the design of the back.
Carefully remove the round plastic piece with tweezers or by hand. Specific to these watches, you will see that Fossil (maker of Relic watches) places a round plastic piece for water resistance, some of which covers the battery underneath the back piece.
Remove the battery replace it the new one. All watch batteries have a style number so that you can correctly choose a replacement from any small electronics dealer.
Replace the plastic cover after securing the battery. Usually you will hear a click to know it is properly fastened.
Pop the back onto the watch, or use the tool to screw it back on. Be sure it is properly sealed as to retain its water resistant abilities.