Confused about the ToR process once approval is given

Hi there, I have applied and received approval for a ToR recently, to bring pre-owned personal items from New Zealand to London. I have owned the items for longer than 6 months and they will be used for my personal use only, now that I have moved to the UK. The ToR approval letter states that I must now complete "an import declaration if the goods that you’re bringing to the United Kingdom are entering the country separately to your arrival." My mother will be sending the items to me, via a international courier company (i.e. not a removal company). My question is, how do I complete the Import Declaration myself? I have spent a few hours this morning going through the material on the HMRC website, and it seems very complicated, and it also states that I need access to a certain software (perhaps CHEIFS) to be able to log my Import Declaration. Also, does my ToR mean that I am relieved of the requirements to pay import duty, import charges as well as VAT? I would've thought I would just fill out a form with my URN and the details of my items, attached it to the box and away it goes, but it doesn't seem to be that simple. Any assistance would be greatly appreciated. Thanks

Hi fbeggs,
Import declaration will be submitted by the courier, please contact the courier and let them know that you have been granted TOR relief.  
They need to complete declaration correctly to claim relief providing the TOR reference is still valid.
Thank you.