How Can I fix Brother mfc-j870dw Wireless Printer Setup

I have purchased new brother printer from a branded retail store. I want to set up brother printer simply, but I don’t have complete knowledge to set up brother printer to Wi-Fi network. I have taken the help from trained technicians. I am facing technical troubles related to  Brother mfc-j870dw Wireless Printer Setup  problems. I want to take online help from trained technicians. I am facing troubles like how do I set up brother printer to Wi-Fi? Can you guide me how to set up brother printer to WiFi? Can you assist me in resolving the issue?