How to remove "Trash" and "Workspace Switcher" from unity panel in Ubuntu 12.04

Noway - It is hardcoded :)

Please vote for https://bugs.launchpad.net/unity/+bug/997322
and
https://bugs.launchpad.net/ayatana-design/+bug/790591

workaround with recompilation of sources:
http://askubuntu.com/questions/38789/remove-the-workspace-switcher-launcher-from-unity-launcher/163952#163952