[header] How to transmit audio with a laser pen [title] Read things you'll need [title] Remove all batteries from the laser. [title] Connect a clip lead to the inside of the laser pointer where the battery touched. [step] Usually there is a small spring to which you can attach the clip lead. 
The other end of the battery usually connects to the case of the laser. Since there are many different styles of laser pointer, you may have to experiment with clip lead placement to get the laser to work with the new external battery pack.