[Javascript] How to reformat comboboxes & checkboxes

Hello,
I am absolutely new to javascript, so I am still trying to read up on how to do this (or if it's possible), but I have a fillable PDF and I need to change the properties on all the checkboxes and textboxes so that any character can be typed in each box (yes, text in the checkboxes).

For the text/comboboxes I was manually changing the properties to "None" under Format. 

For the checkboxes I was taking a screenshot of the textbox size and position properties then I would delete the checkbox and create a text box with the same size and position data manually.

It occurred to me that there may be a more sophisticated javascript solution, however, I hadn't found a similar question answered on the forums.

Any information to get me set in the right direction is appreciated! Thank you.