Well, this is a snippet from a service manual which probably predates your -Ai, but I suspect it might be the same mechanics. The center blob on the spindle is a glued on bit of vinyl(?) that covers a screw head.
Originally Posted by samurai_cinema
The trick is finding a replacement lever. It looks as though there are flats on the end of the shaft it attaches to which would prevent rotation. I suppose a really creative and patient (and desperate) owner could operate on a piece of aluminum with file and hacksaw to make a replacement, but it would not be fun!