How To Reduce Price By 21% (VAT Rate) for UK Customers

[DM7]

I hope someone can help clarify this for me. I see a lot of UK merchants reducing their RRP by 20% at the checkout for EU customers, and then EU customers are expected to pay any duty/VAT themselves on import of their goods from the UK. I would love to set up our Shopify so that UK customers see the price they pay reduced at the checkout so that they can then pay the VAT and duty themselves on their import from the EU.

Just wondering how to do this? I'd also love to know how EU merchants (especially Irish merchants) are dealing with the Brexit changes for now and if anyone has any decent suggestions on how to continue selling to the UK but simplifying the issue of VAT. 

Thank you.