Remove Material overhead cost

Hello all,

We are using R12.2.8.

How to remove existing material overhead costs??

For eg: Inter-org transfer

Material cost 1000

Material overhead cost 100

Total unit cost 1100

Now I need to remove the Material overhead cost only.

I tried through backend, MOH cost set it equal to zero but total unit cost didn't update.

After remove the MOH cost, total unit cost will be 1000.

How to achieve this.?

Is there any API for remove existing Material Overhead and update the total unit cost of the material.

Thanks for the inputs.