The best way is to use a sharp razor knife and carefully cut around the tape. This will leave the new uncured paint in place. The only alternative is to wait 24 hours for the paint to dry.
The reason why this happened is that the primer and paint isn't cured. This takes some time. Also, with metal doors the primer and paint is sitting on top of a smooth surface and doesn't penetrate. This slows down the curing process a little.