How can i make a function which has a multidimensional array input, transforms it, and ouputs the new multidimensional array

Input & Output

Back story

(my english isnt the best)

Hey, im trying to build a game that will teach children about words and letters. Im making it with HTML/CSS & JS(little JQuery) and a little PHP. I have build a tree that holds leaves with letters inside it. I want to build lots of levels, but i would have to type a very big array myself(and i know it should be possible to do it automatic).

I would really appreciate some help!

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Problem

I have a multidimensional array which looks like this:

var words = [
    [
        ['SNEL'],
        ['WORD'],
        ['TIJD'],
        ['BORD'],
        [etc]
    ],
    [
        [BORDE]
        [etc]
    ],
    [
        etc
    ],
    [
        ['BEWUSTER']
    ]
];

Im trying to build a function that will output this into:

var modifiedWords1 = [
    [
        ['img/Letters_normal/S.png', 'img/Letters_normal/N.png', 'img/Letters_normal/E.png', 'img/Letters_normal/L.png'],
        ['img/Letters_normal/W.png', 'img/Letters_normal/O.png', 'img/Letters_normal/R.png', 'img/Letters_normal/D.png'],
        [img/Letters_normal/etc]
    ],
    [
        ['img/Letters_normal/B.png', 'img/Letters_normal/O.png', 'img/Letters_normal/R.png', 'img/Letters_normal/D.png', 'img/Letters_normal/E.png']
        [etc]
    ],
    [
        etc
    ],
    [
        ['img/Letters_normal/B.png', 'img/Letters_normal/E.png', 'img/Letters_normal/W.png', 'img/Letters_normal/U.png', 'img/Letters_normal/S.png', 'img/Letters_normal/T.png', 'img/Letters_normal/E.png', 'img/Letters_normal/R.png']
    ]
];

And this:

var Modifiedwords2 = [
    [
        ['S.png', 'N.png', 'E.png', 'L.png'],
        ['W.png', 'O.png', 'R.png', 'D.png'],
        ['T.png', 'I.png', 'J.png', 'D.png'],
        ['B.png', 'O.png', 'R.png', 'D.png'],
        [etc]
    ],
    [
        ['B.png', 'O.png', 'R.png', 'D.png', 'E.png']
        [etc]
    ],
    [
        etc
    ],
    [
        ['B.png', 'E.png', 'W.png', 'U.png', 'S.png', 'T.png', 'E.png', 'R.png']
    ]
];

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Sorry for my bad english, but thanks in advance! Feel free to ask anything!