eWAy Payment Gateway Missing After Update

I recently upgraded from PS 4.0.1 to 4.5.2, but the eWay and Sage Payment gateways are not available in the admin settings page. I can see there is an advanced folder with the PHP for the eWay gateway, but how do I get it into my store settings options? Do I have to copy the code and paste it somewhere? Did the update go wrong? There are a lot of duplicate files in various directories, so without following the code, I'm not exactly sure what code is being executed.

I have programming experience, but the structure of PS is still kind of cryptic. I need to be able to receive US funds and have them deposited in a Bank of New Zealand merchant account. My client has an eWay account and bank account in BNZ, but I can't figure out how to enable his gateway. PS settings still only shows PayPal and Authorize.net.

Please Help ASAP as we are ready to sell. I tried tech support and was told to post here for an answer...keeping my fingers crossed that someone will know.

in the install folder, there is an update SQL Script that you will need to run to update the wa_settings table in the database:
install/scripts/v4.0.1_4.5.x_update.sql

see the "Running the script" section of the "Updating PowerStore 4 to 4.5.x" how to found here for more details:
updating_4_to_45x.php

I followed all the instructions and ran the script previously. I checked the update script and didn't see anything that added the new options for eWay. I did some searching myself and found the settings for the dropdown in the wa_settings table. I found the correct values in a script call synch_settings.sql. Is is safe to run this script without losing settings (like store name)? I manually corrected the dropdown list in the db, but was wondering what else might be missing, so I wanted to check before running a script that will blow away my wa_settings.

you can run the install/scripts/runsynch.php page which automatically execute the synch settings sql script, it should be fine to run that script, it should not harm anything.

OK I logged in as admin to my power store and browsed to <My URL>/install/scripts/runsync.php

The page was blank, but did it run the synch_settings.sql ?

When I did the update I was instructed to copy the content of the SQL file into MySql Admin and execute it from there. Don't I have to do the same thing for synch_settings.sql ?
Was loading the runsynch.php page in my browser enough ?

WA Sales is telling me I may need custom programming services.
Is this true?

just loading the runsync.php page into your browser is enough to run the synch_settings.sql, the runsync.php page is programed to connect to the database and execute the synch_settings.sql file.

  WA Sales is telling me I may need custom programming services.
Is this true?  

if you are trying to modify Power Store to add functionality that it does not already contain, and need assistance with it, then you may need custom programing services.