What language background are your students? Can you speak a bit of their L1? Do they know the English alphabet? If so, you have a few more options. If they can't read or write in English you have a tougher job on your hands.
Assuming they know the alphabet and its corresponding letter sounds, here are my suggestions:
-Don't bother with content that would be way too hard. It will just demoralize them and you could end up with behavior problems. I'd use the level 2 stuff with them, but intersperse it with materials from elsewhere so that they don't feel like they're in first grade. If you make it clear that you respect them as people and want to help them learn, and that you understand that the material may not be ideal, you'll probably have a smoother ride.
-Try to find out exactly how much vocab they do know. Make a collaborative vocab wall, and encourage them all to use personal vocab journals so they can record the words they learn from each other. To do this, I'd get a big sheet of chart paper and separate it into sections. Head each section with a theme like 'animals' 'food' 'sports' 'verbs' etc. Draw a little picture alongside every header so they can remember which is which. At the beginning of each class, get the students to help you brainstorm words for each category and add them to the chart. Ask them to act out/draw a representation for each word so that everyone knows what the word means. I'm also assuming that your students are all from the same language background. If so I'd definitely have them write the word in their L1 as well, although some schools don't really like that. Revisit the chart each lesson and give them points if they use the words from it in their writing/speaking.
-Have them use bilingual dictionaries.
-It's hard to get students of that age engaged if they are shy, but everyone likes talking about themselves. Make a visual questionnaire by drawing boxes and putting a smiley face in one, a frowny face in another. Draw a blank TV set, a blank computer, and a blank house. Then show the students how you fill in your own questionnaire, by drawing things you like in the box with the smiley face, things you dislike in the frowny face box, you favorite TV shows in the TV box, what you play/read online on the computer screen, and yourself at home with your family/room mates/pets in the house. Then have them do theirs. If they have no English at all, they can just draw. You can then give them the vocabulary to talk about what they've drawn. So if they've drawn themselves with a dog, you can give them the word 'dog', and the sentence frame 'I have a dog'. The more interest you show in them, the more they'll be willing to talk. Bring in some photos of yourself outside of school and encourage them to do the same. Then give them sentences and vocabulary to talk about the photos. 'I went to disneyland' etc
-You could split the class time between working from the coursebook and working on their own projects. The classes I've taught all love this. Once you find out what they are interested in, have them research it and make a poster/book/powerpoint presentation/youtube video/class blog about their particular area of interest, be that their favorite sport, computer game, animal, etc. Having an audience beyond yourself will give them a bit more motivation. Each class they have to draw something and write something. They can look up information in the first language and then translate it into English. You can give them the vocab words they need and sentence frames like 'Did you know that xxx is xxxx?' (look at their drawings to work out what words and sentences they will need to label them). That way they work through the course book and get the reward of working on something they are interested in when they are finished. You also don't have to prepare anything extra :)
Best of luck, hope all goes well!