changing a specific keyframe value

In attack animation clips, I want to change position too.

There should be just three keyframes for it: The first and the last one are the same as the enemy's position and the second keyframe is where our enemy's heading to. And since enemies don't attack to a fixed spot, I need to change keyframes' value from code every time.

How can I do that? (it would be nice if you write the needed code too)

Note: attack animations are in an animator named "Slime" if that helps you write your code easier