How can I stretch portion of a model along a plane/axis? Please see image here for what I'd like to do: 



I want to add stretch a portion of the part by 1mm-2mm right at the location of the plane in the image, along the Y (green) axis. This will increase the distance between the screw hole and the cylindrical portion of the part.

What is the easiest way to go about this? I've used a lot of CAD software in my time but learning Blender seems a bit more challenging. I've messed with a few things but the operation I want doesn't seem to be called what I think it'd be, or I'm just doing it wrong.

Help would be appreciated! :)
First you have to configure Blender to work with measurements, enable snap, select increment option (if I am not mistaken enable snap is not needed but do it just in case) then select the part that you want and press G, Y, - (if you want to move it to the right, don't add a - symbol, + means right, but you don't need to place + because it's implicit - blender assumes that) then the value that you want to add (1 or 2 for example). For a more thorough explanation, see this tutorial: https://www.youtube.com/watch?v=kOxN4CHeBPQ