How do you change the battery in a Concepts CN25070PM watch?

To change the battery in a Concepts CN25070PM watch, first, remove the case back using a case knife or a small flat tool, being cautious not to damage the watch. Once the back is off, carefully take out the old battery, noting its orientation. Insert the new battery in the same position as the old one, then replace the case back securely. Finally, check that the watch is functioning properly before wearing it.