Use TCL commands to remove a file assignment in a project

I'd like to know how I could use TCL to remove a file assignment from the project. For example. I have top level file assignments that are set by a top level TCL like this.

set_global_assignment -name VHDL_FILE file1.vhd

set_global_assignment -name VHDL_FILE file2.vhd

set_global_assignment -name VHDL_FILE file3.vhd

set_global_assignment -name VHDL_FILE file4.vhd

How do I remove file3.vhd with a TCL command for instance. There is a -remove option in the set_global_assignment which does not work. There is also a remove_all_global_assignments, but that would remove all the files. I only want to remove one file. Thanks.