I am a Civil Engineer and I plan to work remotely from UK to Greece (I am Greek).What tax arrangements do I need to make?

international taxes go through the countries customs. So filing taxes would go through the customs and be from the country of predominate residency.

If you're employed, your employer will pay tax in the country they / your job is based in

As I imagine your income will appear in a UK bank you need to declare it to HMRC. If tax has been taken in Greece that will be noted and you may not have to pay any UK tax. You can always phone HMRC for advice. But getting though is not always instant!