Every question dealing with uninstalling/disabling plugins for Eclipse Juno mentions an Uninstall button but I simply can't find it and Eclipse's help for Juno is sadly no help.
Has this ability been eliminated or omitted or is it in some place different for Juno?
The Uninstall... button is available from the About Eclipse dialog. From that dialog click Installation Details and it's under the Installed Software tab. This typically is only available for features, not plugins. If you can find the appropriate feature that contains the plugins you want to eliminate, that should do the trick for you.
If you are unsure of the feature containing the plugin, you can attempt to go the Installation History tab in the Installation Details window and try to Revert to a previous version of Eclipse that didn't have the plugins.
Finally, you can always manually go into your Eclipse installation folder under the plugins directory and remove them manually. This will sometimes require that you run eclipse -clean from your command line/terminal to truly get rid of the plugin. This is probably the most error prone approach as you could cause problems with features/plugins that may depend on the removed plugins.