How to update record as other user

[Shalika]

I have 100 incidents to close using background script. How can I update and close these incidents as other user

[Shalika]

I want to update from background script 

[Bhavana Reddy]

as suggested by Abhijit you can write On demand scheduled job ( you can run that Job once whenever you need it) 

[Abhijit4]

What is exact problem running via scheduled job?

If you need it via background script then some workaround needs to be used.

e.g. you can modify updated by field via same script and use autoSysFields(false), so those will look like updated by some other user.

Please mark answer as Correct or Helpful based on impact.