In Illustrator it's easy to convert a 2 bezier handle anchor point into a end point (containing no handles) with the anchor point tool - as I did in my attached image:
Is it possible to convert that end point (containing no beizer handles) back to a 2 beizer handle point (like it was to start with)?
A better option than using the 'Convert Anchor Point Tool' is to use the 'Direct Select Tool'. After selecting the tool then HOLD 'option' or 'alt' (You will get a '+' mark on the side of tool).
This will allow you to select individual anchor point handle's, instead of the pair.
More information on editing objects