R22 is very easy to charge what i use to do is on high side intriduce liquid and wait till the pipe unfreezes and stop it. Turn it on an turn the bottle and charge vapor of course with the manometers with outside temp 28 -30 degrees you should have it around 60 on low side and high side 225 , remember if the house is too hot your low side will be high so do it with patience, by the way r22 is not available any more at least here in spain.