The top pipe connector (3/4" female pipe thread) is also the filling and emptying plug.  The beaded self-indicating silica gel desiccant should be replaced once the color has changed from blue to pink, as indicated on the label attached to the breather.

Maximum torque on threads is 9 N•m (80 in. - lbs.)

Full installation and maintenance instructions are supplied with each Transformer Desiccant Breather.