lambda-Amazon EC2:Remove instance termination protection if enabled and terminate instances

I have following task:

1.Check if the instance has a tag “Terminate_On”

If yes:

2.Check if the instance should be terminated today

If yes:

3.Remove instance termination protection if enabled Terminate the instance

I’m stuck on part 3: don’t know how to remove protection if enabled and to terminate instance

import boto3   
import collections     
import datetime     
import time     
import sys 

ec = boto3.client('ec2', 'eu-west-1')     
ec2 = boto3.resource('ec2', 'eu-west-1')     
from datetime import datetime
from dateutil.relativedelta import relativedelta

date_after_month = relativedelta(days=7)
#print date_after_month.strftime('%d/%m/%Y')'%d/%m/%Y')

def lambda_handler(event, context):           
    instance_ids = []
    reservations = ec.describe_instances(     
            {'Name': 'tag:Owner', 'Values': ['Unknown', 'unknown']},     
    ).get('Reservations', []) 

    for reservation in reservations:
          instances = reservation['Instances']
          for instance in instances:
              tags = {}
              for tag in instance['Tags']:
                tags[tag['Key']] = tag['Value']  
                if 'TerminateOn' in tags:  
                  if tags["TerminateOn"]==today:
                    #remove termination protection if enabled
                    #terminate instance
                    print "No need for termination"
                if not 'TerminateOn' in tags: