Unfortunately, you won’t be able to change the value of UPDATE PRIVILEGE because it’s set on the attribute itself.
If you go to Active Directory Users and Computers > View > Select ‘Advanced Features’, you would be able to see Attribute Editor when you right click an object > properties.
There are some values that can be changed (e.g displayName) as long as you’re domain admin / account owner
So for those with “This value is set by the system”, it won’t let you change the value/Update privilege itself because it’s system-only and they are not intended to be modified by a user (or us that’s impersonating your domain admin).