Where is training model in deep-q-learning and experience replay section of algorithm

I have a problem in understanding the training section of deep-q-learning in the paper of Deepmind. https://www.nature.com/nature/journal/v518/n7540/pdf/nature14236.pdf

In its algorithm, where is the section of training? How we can train and how we can test this algorithm? Also, which section is experience replay section?