Only 3 wires in 3 phase motor terminal box
It depends on the motor -- but a motor rewind shop* should be able to do this, particularly if the terminal box already has a place for those three wires to go.
How much it'll cost depends on the details of how the star connection is done inside the motor -- if it's buried under a bunch of windings, the motor will need to be completely rewound.  You won't find that out until the rewind shop has it open and is looking at it.
* Your use of the term &quot;engineer&quot; suggests that you speak British English and not American English -- I'm not sure what the name of the shop would be in British.  But if there's industry that uses motors, there will be shops that rewind them.