@BinhDT,
If you have a specific add-on/toolbar you'd like to install, go to the site while your default engine is changed to Trident. If you'd like to browse through a list of the IE Add-ons, you can go to their gallery (
http://www.ieaddons.com/en/) using Lunascape with Trident and proceed steps. Once successfully complete the installation, go to View > Toolbars and click the one you've just installed, so that it will show up in your toolbar area (a show-up place might be different depending on Add-ons).
For Webkit, you'll need a lunascape add-on (for Webkit) if you'd like to have one.
Hope this will help.