Removing the reverse idler gear (H55F) (1 Viewer)

[fullthrottle]

It's got me a little stumped as to why I cannot tap the shaft out in the direction of the arrow.
Is the woodruff key holding it in place, or just stops the shaft from spinning?

 

[Eurasiaoverland]

There's a big E-clip on the reverse idle shaft on later (1985+ I think) H55Fs, which the manual does not show. It should then come out with a drift.