I bought my S5 from a Canadian carrier which had network locked the phone.
All it took to unlock my S5 was a simple unlock code and a sim card from an alternate service provider.
Depending on where you look, you can find unlock codes online for varying prices, I bought my unlock code from cellunlocker.net and it took me roughly 5 hours to receive the code via email from them. All I needed to do afterwards was input the provided unlock code and my phone was instantly network unlocked.
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