This is an old koan, readily familiar to those of a certain reading list, and immersed within certain cultural habits.
My own two cents is that it is impossible to meet the Buddha, because he does not exist. Given this, there is nothing you CAN kill. The Buddha spirit is quite safe, and so are you, as long as you are committed to death.
This is offered in the spirit of facilitating perceptual risk taking.
If this is cryptic, shouldn’t it be?