[Verizon Samsung Galaxy S III] lair12:
Just take a look at my file and it should make some sense. Each APN starts with "<apn name" and ends with "/>". It is simple text editing using the DB Text Editor that seems to come with the Dropbox app. Alternatively you can transfer the backup file to your computer, edit it in Dreamweaver or another program, the transfer it back to your phone, before finally doing the restore through HiAPN.

<?xml version='1.0' encoding='UTF-8' standalone='yes' ?><apns>

<apn name="Verizon Internet" numeric="310004" mcc="310" mnc="004" apn="VZWINTERNET" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default,dun" />

<apn name="LTE - Verizon Internet" numeric="311480" mcc="311" mnc="480" apn="VZWINTERNET" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default,dun" />

<apn name="EHRPD - Verizon Internet" numeric="311480" mcc="311" mnc="480" apn="VZWINTERNET" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default,dun" />

<apn name="MTS Internet 01" numeric="246081" mcc="250" mnc="01" apn="internet.mts.ru" user="mts" server="" password="mts" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

<apn name="Beeline 28" numeric="246081" mcc="250" mnc="28" apn="internet.beeline.ru" user="beeline" server="" password="beeline" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

<apn name="Beeline 99" numeric="246081" mcc="250" mnc="99" apn="internet.beeline.ru" user="beeline" server="" password="beeline" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

<apn name="Megafon 02" numeric="246081" mcc="250" mnc="02" apn="internet" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

<apn name="Megafon 30" numeric="246081" mcc="250" mnc="30" apn="internet" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

<apn name="DNA 03" numeric="246081" mcc="244" mnc="03" apn="internet" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

<apn name="DNA 12" numeric="246081" mcc="244" mnc="12" apn="internet" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

<apn name="Elisa 05" numeric="246081" mcc="244" mnc="05" apn="internet" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

<apn name="TMobile" numeric="246081" mcc="310" mnc="260" apn="epc.tmobile.com" user="" server="" password="" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="internet,mms" />

</apns>

This was the additional line I made for MTS to work in Russia and included it in my fileabove.

<apn name="MTS Internet 01" numeric="246081" mcc="250" mnc="01" apn="internet.mts.ru" user="mts" server="" password="mts" proxy="" port="" mmsproxy="" mmsport="" mmsprotocol="" mmsc="" type="default" />

If your format is wrong, it won't load in HiAPN.

You will definitely have to put in an apn name (which shows as it's given name), an apn (which it key and needs to match what the provider wants, and you should probably find and add the correct MCC and MNC. Some providers seem to have user and passwords that go in their respective spots. You can see where I was prepared for Megafon or Beeline SIM cards as well.