Richard,
Remove the band by depressing the spring loaded barrels located in watch/wristband attachment.
Remove the 4 screws,remove the stainless cover gently so as to not damage the seal,remove the white plastic cover.
You now have to un-clip the battery restraints using a safty pin.(be carefull).Replace the batteries and re-assemble the same way you dissassembled,use vasoline(pertrolium) jelly to hold seal in plece when putting the stainless cover back on.Do not over tighten the screws.
garyfarrugia@yahoo.com.au, July 2007