New phone

[KM9]

How can I switch my account from my current phone to my new phone?

[BKNS27]

@KM9 

Just take out the SIM on your old phone and put it in the new phone. You might have to remove or install a spacer depending on the SIM tray size.

Reboot your phone by powering off the phone then power back on.

eSIM…can’t be done yet.

[Handy1]

@KM9  Take SIM card out of old phone and put it in new phone that’s it nothing more . Easy peasy 

[softech]

@KM9   you are using physical sim and not esim?

all you need to do is to remove the sim from old phone, put it in the new phone and it will work.  Beauty of physical sim

Of course, you might want to backup your data from the old phone to cloud and then restore it to your new phone to make setup easier

[Yummy]

You just have to pull out SIM card and stick it into new phone. Use appropriate SIM adapter is SIM slot is different.
eSIM is not transferrable, yet.