Post war zw

if I remember, look at handle,  see a little hole at end, in center,,,4/40 screw,

According to the Kline repair manual, it says to use a 4-40 X 1" screw.  

"To remove the plastic throttle arm without disassembling the transformer case, screw a #4-40 X 1" machine screw into the opening in the end of the throttle arm dial.  This will push the throttle arm dial off the shaft."  At the top of the round domed end is a tiny hole, which is where the screw goes in.  I presume that you just have to press or push the new throttle arm back onto the shaft, but make sure it is the correct position.

Haven't done it myself but Dave Gemmell posted this video about it on Youtube;