Ok let me break it down. I figured I would give it a try, since I have the same Alt as you. Ok first off the tolerances between case and coil are like 1/1000th of an inch with a depth of about an inch. So prying wont work. I tried with every tool I have. Then I figured its covered in oil, so no stickion (sp). If I can equalize the pressure its should slide out.
I cut a piece of 1/4" scrap to about 80.25mm x 25.5mm I was too lazy to press the button on my mic to convert to SAE.
Then place the metal inside the case on the back side of the ALT like this:
Hold your finger on the metal to keep in in place while you flip the case over to the alt side and you will see the metal through the ALT cover. I used minimal pressure and it slid out like buttah!
How it rests on the ALT from the backside, you just have to distribute the force equally!
All in all about 5 minutes of work! The metal I cut roughly with my sawzall, you can see it crooked, then de-burred with a sanding wheel. I dont want any burs inside my case. Then get some SXL wire, or send it to me and I can build you a new harness, using weatherpaks and SXL wire.