The plastic part of the latch you must push to open the dishwasher broke.

I looked up the part number for the latch assembly on the internet, part mumber 2180046, Latch handle(handle and door latch complete assembly with switches-white). Upon receipt, which was within 4 days of ordering it I installed the latch assembly. To install the latch assembly I had to remove 11 screws, using a nut driver with a #25 star bit attached, This allowed me to remove the inside of the dishwasher door to gain access to the latch assembly. The latch assembly had two double pronged electrical connectors attached, one on each side of the assembly. I found them very difficult to pull off, but they finally came off.
When you do this you must take careful note as to the the positioning of these connectors so you can reinstall them to the new latch assembly correctly.
After attaching the electrical connectors to the new latch assembly I ensured it was in the proper position as I reattached the inside of the door with the 11 screws previously removed. The new latch was relatively easy to install and it works prefectly. Our 1980 Matag dishwasher is now back in operation, working as well as it did when it was new.