I have a ’69 25 hp with a bad kill switch in the shop, so I went and pulled it.
It’s hard to get to the 3/4" mounting nut without taking the carb loose, but having done that I see that the switch body can probably be rotated from the front.
(Sorry for the bad pics.)
The lanyard switch was got from Amazon: https://www.amazon.com/gp/product/B00DH … UTF8&psc=1
The original has a 5/8" shank and the new one a 9/16" shank, but I doubt that is a problem.
Otherwise, just need to cut the leads and crimp on female spade terminals.