Have the batteries changed at a qualified specialist workshop.

WARNING
Batteries contain toxic substances.
Swallowing batteries can lead to serious health issues or death.
Keep batteries out of the reach of children.
Seek medical attention immediately if a battery is swallowed.

WARNING
The SmartKey batteries contain perchlorate material, which may require special handling and regard for the environment. Observe government disposal guidelines. California residents, see www.dtsc.ca.gov/HazardousWaste/Perchlorate/index.cfm.