It is really easy. First take off the tailgate and the glass lift hatch. Then you are done.
You can't unless it has a remote trunk popper on the unlock remote. I had the same problem and went to an Isuzu dealer for a new key and remote.
How do you replace the tailgate lock on a isuzu wizard 1999
The jack is in the left rear corner. Open the tailgate and remove the cover on the inside panel. The hardware is under the passenger rear seat bottom. Lift the seat forward and it's clipped to the bottom of the seat.
With the "barn doors" there is no way to open the windows. With the top glass and lower tailgate you can either insert the key into the tailgate like you would a door and turn it to "pop" open the glass. OR there should be a button to the left of the stereo (below the rear windshield wiper control) that will "pop" the rear glass.
I have an 07 and the glass hatch opener is to the right of the rear hatch opener. It is much smaller though.
If the glass will open, you can just use a slotted screwdriver inserted into the key slot to drop the gate. Takes a little pressure, but it will work. If it doesn't, and the glass doesn't click when closed, the hinge inside is stuck. You can push on it with the screwdriver and it should move. then try the screwdriver in the key slot again and it should drop the gate.
change you thermostat it is stuck open or not closing fully. This allows the coolant to circulate to quickly.
Get someone to hold the hood release lever while you pull up on the hood.
To open the trunk, for a 1993, next to the steering wheel there's a button that says tailgate open, push it. Then go to the back and where the spare is attached to there is a lever on your left that you have to flip towards you, flip it, and at the same time there's another lever right behind that spare you have to pull towards you. that releases the spare away from the door, the window should open and with the spare out of the way you can open the door.
Behind the seats on the passenger side if the compartment is pulled open there is a release in there. Just pull that lever and the tailgate will open.
See www.isuzufaq.com entry 41. "How do I reprogram my keyless entry fob?" The first procedure (turn key 3x, close & open door 2x, turn key 5x, close & open door) worked for my 2002 Rodeo.