[wereHamster]

Getting to the sun is really hard. Any object flying at earth's orbit has so much energy that you need to reduce in order to get to the center. The probe simply doesn't have enough propellant to slow down that much. The only other way that I can think of is to perform a gravity assist that would send the probe straight into the sun. And if you miss, the probe becomes a molten blob of metal that will forever continue flying in a highly eccentric orbit around the sun.

[didgeoridoo]

You don’t need to cancel out the velocity with respect to the sun though, since you aren’t trying to land on it, or even trying to enter into a circularized heliocentric orbit. The first two burns of a bi-elliptic transfer (as if you were attempting to insert to a nonexistent Earth orbit at the sun’s altitude) should put you on the right trajectory I think?