To delete the references to the units in the uses clause(s), use the menu "Source->Refactoring->Unused units", which can also be accessed through the pop-up menu of the editor.
If that doesn't work then you'll have to do it by hand, deleting the offending references in the source. Note that hovering the mouse pointer over a control/component class will tell you (most of the time) in which unit it's declared. Also, compiling after each deletion will allow you to ascertain whether the deleted unit is still "used", somehow, in your code (look for "Identifier not found" errors).
Package dependencies can be deleted in the Project Inspector (menu Project->Project Inspector). Again. compiling after each deletion will tell you whether the dependency was really needed.
HTH!