Tips for learning to write scripts.

That is possible, but certainly not a "starter" script. I wish I had time to write it for you, but perhaps you can find someone who already has something close. In the mean time, I suggest you start with something a little easier and work your way up. For example -

write a script that reads the commands in the part program and displays their type information
then tell it to only display the command information if it is a dimension
then tell it to display the axis fields for those dimensions
then tell it remove it from the edit window if it is a certain name
then have it display a dialog and ask you which dimension name to remove using a text input
then convert the dialog to use a listbox and allow you to select one dimension name to remove
then code the listbox to allow for multiple selections for which dimensions to remove
and so on

I am not trying to be sarcastic here, I hope you don't take it the wrong way, but that is how I would proceed to develop that sort of project, one piece at a time, saving each one along the way.

That is possible, but certainly not a "starter" script. I wish I had time to write it for you, but perhaps you can find someone who already has something close. In the mean time, I suggest you start with something a little easier and work your way up. For example -

write a script that reads the commands in the part program and displays their type information
then tell it to only display the command information if it is a dimension
then tell it to display the axis fields for those dimensions
then tell it remove it from the edit window if it is a certain name
then have it display a dialog and ask you which dimension name to remove using a text input
then convert the dialog to use a listbox and allow you to select one dimension name to remove
then code the listbox to allow for multiple selections for which dimensions to remove
and so on

I am not trying to be sarcastic here, I hope you don't take it the wrong way, but that is how I would proceed to develop that sort of project, one piece at a time, saving each one along the way.