How to delete an old inactive assignment

Hello Experts,

Could anyone tell me if there is a way to delete an Old Inactive assignment and make the current assignment as the first assignment for an employee?

Background:

We have re-hired an employee by adding a new Assignment to the previously terminated profile. But the person is not supposed to be re-hired and now old, terminated hire date is showing up as the employee's enterprise seniority date which is incorrect. We have other genuine re-hires for whom we want to preserve the enterprise hire date to calculate correct long service leaves. If there is a way to manually adjust the seniority date, would that help here in this case?