If you haven't done so already, head over and sign up with Paylike and create a live account.
Download the module for Drupal Commerce 7 or 8 depending on which version you use directly in Drupal's module marketplace.
Go to the module's readme and follow the installation instruction for Drupal Commerce 7 here or for Drupal Commerce 8 here.
Drupal Commerce 7
Drupal Commerce 8