how to change data-value on div by JS

I am working on a project that I need to change attribute of data-value by js language.

You can see the code here.

<div class="col-sm-4">
    <div class="ldBar auto no-percent label-center m-auto" id="tree"

    style="height: 300px; width: 300px;">>>>>>data-value="50"<<<<<<

     data-type="fill" data-img="tree1.svg" data-fill="data:ldbar/res,bubble(#f00,#d00,100,1)"
     data-fill-background="#ddd"
      data-fill-background-extrude="0">
      <svg xmlns:xlink="http://www.w3.org/1999/xlink"
      preserveAspectRatio="xMidYMid" width="100%" height="100%" viewBox="-4.5 -4.5 109 109">
      </svg>
      <div class="ldBar-label"></div>
    </div>
  </div>

As it seems data-value is set 50. By this I am just making image fill up to 50 per cent. But I want to change this value automatically. A Js code that makes it lets say 25. How can have this access to change this value?