How to install BOL (Branding On Load)?

The way to do it is add to the code page a few lines:

var header = document.getElementById("customBrandBar").tBodies[0]; //get the tbody element

//this line is optional if you want to change the background color.header.style.backgroundColor = "red"; 

var tr = header.childNodes[0];

var td = tr.childNodes[1];

var img=document.createElement('img');

img.src="the logo url";

//this line is optional if you want to resize the image
img.style.height = '7%';

td.appendChild(img);