Hitachi ZAXIS 135US-5B Operator's Manual page 363

MAINTENANCE
2. Driving out locking pin
Remove pebbles, dirt, etc., completely from the gap
between lock pin (3) and adapter (2). Place pin-removing
jig on the top end of lock pin (3) and hit it with hammer
to remove lock pin (3).
When driving out the pin, first hit with a shorter jig until
top end of lock pin (3) comes to the upper end position
of the lug of tooth point (1), and then use the longer jig
to remove lock pin (3).
3 2
1
3 M116-07-126
7-89