Change the value of the cell if part of it matches

Dear Experts,

i have column with with a drop-down list. How ever some of the value doesn't match the value in drop-down list as the user selected a value and dragged it resulting in increments in the value. For example:

Current Value
System Technician 825
System Technician 826
System Technician 827
Maintanence Technician 825
Maintanence Technician 826
Maintanence Technician 827
Maintanence Technician 828
Maintanence Technician 829


Correct Actual Value Should Be
System Technician 825
System Technician 825
System Technician 825
Maintanence Technician 825
Maintanence Technician 825
Maintanence Technician 825
Maintanence Technician 825
Maintanence Technician 825

Pls help as to how i can go about making the change?