How can I change door of Fisher & Paykel refrigerator?

Depends on the model - if you have a door with the handle fixed to the front face of the door, then you will need to buy replacement doors. You may also need new hinges and support brackets to change from RH hinge to LH hinge. Try listing on your local e-bay or trademe site to see if you can swap with someone going the other way to you!
The doors are available on line from fisherandpaykel.co.nz - follow link to customer service, then Spare Parts then click on Parts Search. You will need your model number.You can also send a mail to their service guys and they reply quickly - worked for me :-)

John
October 2007