I'll do another step-by-step.. Since there was some guesswork when I did it.
1- Use Google, Search "Navifirm" and click on the first result. At the bottom of the first post on that page, there is a link(no registration required) where you can download it. Save it somewhere easy to access.
2- Use Google again, or your preferred Torrent site. Search "Phoenix Service Software" and download/install it. (2010.12.008.42304 is the version I used)
3- Open navifirm.exe. It will take a moment to load the product list, so be patient
4- Select Nokia 5230 (RM-593)
5- Under Releases, select 12.8.95
6- Under Variants, select RM-593 CTR AWS NA WHITE_WHITE (0595971)
7- Above the list of files, click "All"
8- Click "Download from FiRe" at the bottom right.
9- Navigate to %Program Files%\Nokia\Phoenix\Product and save the files there.
10- Open Phoenix, Go to Tools > Options > Product Location
11- Add C:\Program Files\Nokia\Phoenix\ and C:\Program Files\Nokia\Phoenix\Products and click apply(it will prompt you to add locations for DP2.0, just use the default), then click Close
12- Connect your phone VIA USB.
13- Click "File> Scan Product". At the bottom left it will tell you the status. When it is complete, you will see "Operating Mode: Normal" under "Connections".
14- Click "Flashing > Multiflash"
15- Under Dev. 1, select USB1
Under Product, select "CBL..."(not sure if everyone's number after CBL is the same)
Under software, select Product(The name of the folder you put the files in)
Code should be "0595971 RM-593 CT.."
Version 001
Method: Refurbish.
16- Click start. Do not interrupt this operation, so make sure your phone is FULLY charged.
Also, when going to update, be sure to press yes as quickly as possible to allow s/w update to connect to the internet.
Took me two times(got it on the third attempt when I realized what the problem was) to get the list.
Not sure if this is accurate, but it seems that it tries to connect once and if it can't, it will throw the error. If you click to allow it to access the internet quickly, it wont give the error.