By boiler is reading the maximum pressure and I am not sure how to release the pressure if you know please let me know thanks stevie

By law, all pressure vessels have to be equipped with an over-pressure (safety) relief. It should open at a setting of a few pounds above the maximum working limit of the boiler. The pressure should be stamped or tagged somewhere on the relief valve. If it fails to operate properly, shut the unit down and have the relief valve replaced, then retest the system.

It also sounds as if your pressure regulating control is out of adjustment. You really should call a professional contractor to service this unit. A boiler is a bomb if its safety and control devices are not working properly. You can't believe how much damage a boiler can do when it explodes.