horn help

[Crazeecooter@aol.com]

I am trying to install the horn button on my TR6 (new---ordered from TRF)  
However, I can't seem to get it to fit in because there is this little 
plastic triangle on the top of the backside of the button that is preventing 
me from inserting into the steering wheel.  Has anyone encountered this 
problem?  Does the plastic triangle need to be filed down?

any help would be greatly appreciated

jonathan