Had the same problem last year ans I obtained the part by post from Hotpoint. I ensured electrics turned off and removed the lid of the machine by unscrewing the screws at the back oif the top. Its a bit tricky, but I had to place the hinge in the right place on the front and used tape to hold it, reached down the inside of the machine and placed one screw in through the back to the relevant hole in the hinge and manually screwed in, then tightened with screwdriver, making sure the hinges was held in place and then screwed in the other screws.
noreen, March 2008