The easiest way is to pop into a store and they'll swap it over for you and give you a QR code. Just check if you need to book an appointment in advance and the store is open, and all that.
You can call and EE will send you an eSIM pack out but that;'ll cost you £1.50 and take a few days.
As long as you have an unlocked iPhone (or locked to EE), it's a simple process to swap over.
@MATTHEWR Just to add if your device is an EE device it’ll be locked to EE and this means only EE sims will work in it. Once you had the device for over 6 months you can request it to be unlocked HERE to then use any network sim you want in the device.
To contact EE Customer Services dial 150 From your EE mobile or 0800 956 6000 from any other phone.
