You need a narrator, and two people to speak the words of Philip and the Ethiopian. The narrator reads from a lectern or central place. Philip and the Ethiopian begin beside the narrator, walking slowly round the worship space, ‘talking’ to one another – although the only words spoken aloud will be those in the text – and arriving near to the place of baptism by verse 36. Pause the reading to act out the baptism. Then Philip and the Ethiopian go separate ways – the Ethiopian returns to the side of the narrator, celebrating all the way. Philip disappears by whatever route is easiest in your context.