1. download Mozilla Firefox 2.0.0.1 web browser
2. install Sketcher 1.0.1 extension for Firefox

The 'sketcher' icon should automatically appear on the custom toolbar.
If this does not occur then Right-click the toolbar area - and select 'customize' from the pop-menu.
Find the 'sketcher' icon in the 'customize toolbar' window and 'drag' it into your browser toolbar.