Re: Mercury Thunderbolt 500 control wire detachment.
For the top cable, there is a spring-loaded black lever holding it on to the linkage assembly. Pull the lever away from the linkage and turn it at a 90 degree angle to the linkage. Pull the cable away from the linkage towards the side of the engine and it will come off.
For the bottom cable, the silver clip with the slot in it needs to be moved. There is a flathead screw visible in your pic-loosen that, lift and slide the slotted bracket towards the rear of the engine. The cable should pull straight up and off of the linkage.