I'm assuming it's a metal tip? I'm not even sure they make plastic ones...
Anyways... Go to your local hardware store... pickup some sprayable paint stripper... would be in an aerosol can... give the tip a nice light coating of that stuff... It should take the paint off it
Now when you want to get it ready for paint... get yourself some latex gloves and some good degreasing dishsoap... wash it... but from this point on you don't wanna touch it without having the gloves on... the gloves keep the oils from your fingers off the piece which will affect the quality of paintjob
get some automotive primer... the grey stuff is the colour you want... not the red...
Again, a nice light coating from about 10 inches away... It's better to put 2-3 light coatings on rather than one thick one on or you'll end up with runs in the paint...
Then find yourself whatever color it is that you want the actual tip to be and do the same thing.
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