1) Watch Case Back Opener Knife, 11.5cm (4-1/2")

2) Pocket Watch

3) KAG4/377A Alkaline Battery, 6.8x2.6mm (Usually, this battery can work 3-6 months).

STEP 1 Use knife prizing up the back of watch.

STEP 2 We can see clearly the inner structure of watch.

STEP 3 Take out the loop which is used to firm the clock mechanism.

      (Some watch does not have this loop, then, skip this step.)

STEP 4 Then, we could get the old battery out.