2008 Toyota Prius Owners Manual - Page 423
2008 Toyota Prius Manual
Page 423 highlights
4 -3 . Do-it -yourse lf m a int e na nc e Ke y bat t e r y Replace the battery with a new one if it is discharged. n You will need the following items: l Small Phillips-head screwdriver l Lithium battery (CR2032) n Replacing the battery STEP 1 Take out the mechanical key. STEP 2 Remove the cover. STEP 3 Remove the battery cover bolts, the battery cover and depleted battery. Insert a new battery with the "+" terminal facing up. 396 PRIUS_U_(L/O_0802)