Central value Contract has two UoMs

For one of the line item in the contract has two UoMs OUn is "KG" and OPU is "EA", due to this accounts team facing payment issue.

We need to change the UoM from KG to EA for the line item so that OUn & OPU should have "EA".

I haev tried all the possibilites to find solution but failed.

This is one of priorty issue so please need your valuable inputs.