How to set value for a field even when the field is read only ?

Content

Requirement:

Based on the “Rental unit” field value, we have to set value for the field “Kpp Ext coverage” and then we have to make “Kpp Ext coverage” field read only.

Challenge:

First it is making the “Kpp Ext coverage” field read only and then trying to set value. Since the field is already read only, the value is not getting set.

Version

Oracle policy automation(Aug 16)