SCOTT - Been several discussions in the last year about repairing the lift lever & float button. Parts are still available.
There's a 90+% probability the inner rod that releases the left lever is broken off on top, or the top button is broken. If the rod is broken, it has to be replaced, is just the top button is broken, last discussion we had, the poster just carefully trimmed some of the top of the lever off, removed the broken button and installed a new one.
But to start, you have to remove the whole lever & rockshaft, remove the two bolts on each mounting bracket under the foot rests, and there's two longer carriage bolts that attach the quadrant the lift lever engages, those come out too.
If you have to replace the inner rod, it has to be installed from "above", and then heat & bent on the bottom after it's installed in the lift lever. The inner rad has to be threaded to allow the top button to screw on, and cut to length. I'd also replace the inner spring and washer when you repair it.
There's a lot more info on the repair in the old discussions, you can find them by doing a search.