Yamaha YAS-108 Owner's Manual page 17

Operating range of the remote control
Operate the remote control within the range shown in the following
figure.
Remote control
sensor
Within 6 m (20 ft)
17
Replacing the battery in the remote
control
Press and hold the release tab firmly in the direction indicated by
[A], and slowly slide the battery holder out in the direction indicated
by [B].
Release tab
En
Battery holder
CR2025 Lithium battery