Need UART pins installed on some boards

I work remotely for a company. I received a few modules that have vias for a UART header (4 pins, 0.1" spacing), and I need to have header pins installed on them. I have the header pins, but I haven't ever soldered, so I don't really want to buy a soldering iron and try it myself. J1 on the picture is where I need to have the pins installed. I have a few units I need this done for.