The following sample code demonstrates how to change the value of a particular node.

C#

using DotNetBrowser; 
using DotNetBrowser.DOM; 
using DotNetBrowser.Events; 

//... 
Browser browser = BrowserFactory.Create(); 
browser.FinishLoadingFrameEvent += delegate(object sender, FinishLoadingEventArgs e) 
{
    if (e.IsMainFrame)
    {
        DOMDocument document = e.Browser.GetDocument();
        DOMElement button = document.GetElementById("button-id");
        button.Children[0].NodeValue = "New Button Name"; 
    } 
}; 

browser.LoadHTML("<html><body><button id='button-id'>Button</button></body></html>");

VB.NET

Imports DotNetBrowser
Imports DotNetBrowser.DOM

'...
Dim browser As Browser = BrowserFactory.Create()

AddHandler browser.FinishLoadingFrameEvent, sub(o, e)
    If e.IsMainFrame Then
        Dim document As DOMDocument = e.Browser.GetDocument()
        Dim button As DOMElement = document.GetElementById("button-id")
        button.Children.Item(0).NodeValue = "New Button Name"
    End If
End sub

browser.LoadHTML("<html><body><button id='button-id'>Button</button></body></html>")