It is best to tame a bird when it is still young, but it's still possible if the bird is grown.

Firstly, I would like to say that it is likely that neither of your budgies will become very t ame, since they have each other for company. Single birds will look to their owners for love and friendship, but if they have a partner, they will seek it's freindship. If you want your budgie to become really tame, you might have to consider re-homing one of them (don't do this if you do not have plenty of time to spend with the single budgie). Some budgies can be quite tame even if they have a companion, it just depends on the bird.

To tame your budgie, you will have to put aside time everyday to hold and stroke it. Talking alone wil not tame the bird. Spend time holding it gently in one hand, and stroking it's head with the other. Make crooning, comforting noises to calm it. At first it will struggle, but in a surprisingly short time, it will get used to being carried. Once it is used to being carried, slowly open your hand, allowing the budgie to perch on your finger. Be ready to catch it if it tries to fly away. Stroke and talk to it. You can also put food on your palm for it to eat. It won't be long before your budgie willbe perching happily on your hand or shoulder.
Just remember, the more you hols and stroke your budgie, the tamer it will get.
Good luck!