Remove the carb from the engine.
Remove the butterfly from the throttle shaft, then you can pull the throttle shaft out of the carb. Now you can solder it without worrying how hot it gets. I just did this with my new G62. Instead of using the plastic arm and set screw method, I ground off the top of the shaft and flipped the stock arm over and rotated 180 degrees, then soldered back on. This also let me keep the return spring hooked up which I like as a safety feature.

Here's a couple of before and after shots. Not the prettiest solder job, but it works.......