Transition to cow's milk

Hi guys. My son is 1 now and have given him 120mls of uht milk without any issues and I'm hoping to transition him off formula completely (and bottle too). Can anyone share any tips pls on what kind of volume of cows milk per day and how to stop being bottle fed? Worried might no get enough iron or other nutrients. My son goes to infant care, takes 3 solids a day (cereal for bfast, porridge for lunch, dinner at home dependa on what we are eating) and can drink from a straw cup. I cant imagine bringing 3 cups to school a day (they dont wash) and open cup maybe abit too challenging due to mess. Thanks in advance!