So, for this I am going to show it in Inventor HSM (but remember that this feature is available in HSMWorks and Fusion 360 CAM.
With our part open I am going to highlight a 2d contour toolpath and you can see that the entry position defaults to start of the straight wall on the part. (see pic below)
Now, I want to move that entry position to be tangent to the larger diameter and on the edge that has the least amount of material being removed (see yellow arrow in pic).
To do this I am going to right click on my 2d contour toolpath and select edit. Next, I am going to the linking tab of the toolpath and down at the bottom is a selection called Entry Position.
Select the Arrow button by Entry Positions and then select a point on the arc of the outer diameter.
Once selected you will then see a green dot appear at location that you selected.
Now, go ahead and click "OK" on the toolpath to generate with the new entry position selection.
This is what will now generate.
Now you can see that the entry position has now shifted to the point that i had selected.
Hopefully you find this tip helpful in your ventures of programming.