Keep things simple. Use plenty of gestures and try to introduce a few very basic phrases without rushing them.
By the end of the class they should be able to say, for example,
"Hello"
"My name is X"
"His/Her name is Y"
And have plenty of practice and confidence to do so. If they are good students and have mastered these easily, by all means using the same techniques of gesture, repetition and practice then move on to further phrases they will find useful:
"I am from London"
"He is from America"
and so on.
There are detailed instructions on this lesson here.