var p = document.getElementsByTagName("p");
for(var i=0;i<p.length; i++) {
if(p[i].innerHTML == "Tea") {
p[i].innerHTML = "Milk";
break;
}
}
<pre>var p = document.getElementsByTagName("p");
for(var i=2;i<p.length; i++) {
if(p[i].innerHTML == "Tea") {
p[i].innerHTML = "Coffee";
break;
}
}