How to simply replace a file in a MSI package with Pacesuite MSI editor ?
We fix the bad value in the config file on a computer where the package was installed, then I would now to get this correct config file and replace the file which is in the MSI (in a Cab file in the MSI) by the corrected one with PaceSuite MSI Editor.
Community Chosen Answer
If its a vendor supplied MSI? do not make changes directly to the MSI, instead create a transform file and include changes/modifications within the transform.
The link above should help you with either editing a re-packaged MSI or section 3.2 provides the necessary information on generating transforms.