Regarding to http://community.jboss.org/message/552490 at this time, there is no possibility to remove drools "nature" (as it is probably not the nature in sense of eclipse nature)

We should be able to remove drools from project. Menu item 'Convert to drools project' should be called 'Add drools nature' and when a project has a drools nature it should be called 'Remove drools nature'.

Maybe it would be good, not to have 'Convert to drools project' menu item in main context menu, but move it into 'Configure' submenu