lockwood16

Hi, My parents have 1998 Camry. The Central Locking Remote has a flat battery and wont unlock the doors. The key works ok. They have been told by their local dealer that they need a new one. It is a sealed unit. Quoted $90. Has anyone replaced the battery in one of these? Also one of the keys has a battery in it. What is this for? Maybe another problem down the track to sort if it goes flat. $90 for pensioners is alot of money.