Do you leave it out free choice for them? If not, definitely start there. Secondly, without momma showing them what to eat, they will pick it up much more slowly. One way to kind of force the subject is to decrease their milk consumption. If they are full on milk, they aren't going to want to eat the other stuff much because they are full.
Thirdly, is there are reason you want to wean them now? You certainly can, but your babies will benefit from another month of bottles... even if it's just like once a day.