Beware that doing this will break all connections with the base project so they will not be able to easily determine when the base project text is changed (i.e. all the status boxes will be gone). Status boxes are very useful to a derived project so I would make certain that they need to use a different versification before preceding.
That being said, the easiest way to change to a Standard Project without losing anything else is to close Paratext and open the Settings.xml file inside the project folder and change the line:
"<TranslationInfo>Daughter:{baseProj}:{LongString}</TranslationInfo>
“
into:
”<TranslationInfo>Standard::</TranslationInfo>
".
EDIT: This should only be done by advanced users.