Tap 'Medications' on the bottom menu

Tap on your medication to edit

Tap on the pen icon on the top right

Tap on your current med reminder time under 'Reminder Times' and change this to your desired time.

When you are finished, tap 'Done' on the top right.

Tap 'Medications' on the bottom menu

Tap on your medication

Tap 'Edit' on the top right

Then tap ‘Reminders’, tap on your current reminder time and change this to your desired time.