YSI Level Scout - Manual (Page 34)

With one finger, gently push downward on the internal
connector until the connector circuit board is at the bottom of
the retaining slot. Rotate the connector and board 35º counter
clockwise until the tabs in the circuit board clear the retaining
slot, figure 4.3.
Once the tabs are free of the retaining slot, tilt the transducer
and the batteries will slide out. They will push the small
circuit board out with them, figure 4.4.
Do not pull or twist the brown flexible cable attached to the
circuit board shown in figure 4.5. Figure 4.5 shows the normal
extension of this cable that is required for easy replacement of
the batteries.
Install two new industrial AA alkaline batteries into the Level
Scout. When installing the batteries, pay attention to the
polarity of the batteries. The negative battery terminal end of
the battery should be installed into the housing first (figure
4.6).
Figure 4.3
Figure 4.4
Figure 4.5
Figure 4.6
32 Level Scout YSI Incorporated