Pressure releif on a pin lock keg

I got a used pin lock keg for Christmas. However, there is no pressure releif on the top lid of the keg. Can I still use it? If so, how do I releve the pressure to release the oxygen before fully carbonating?

Heck yeah you can still use it. To degas press the gas in poppet and this will release any gas. They make special tools for this but I find I can use a screw driver and achieve the same results.

Thanks josh. That worked great.