Plunger repositioning system

An assembly, comprising:

• a plunger having a longitudinally extending socket bore that opens into an enlarged internal chamber;
• and
• a tool, comprising:
• a pair of concentric and relatively rotatable shafts, comprising:
• an elongate and tubular outer shaft;
• and
• an elongate inner shaft;
• and
• a head assembly formed from adjacent coaxial head elements, comprising:
• a forward head element supported by the inner shaft;
• and
• a rear head element supported by the outer shaft and having the same cross-sectional profile and cross-sectional dimensions as the forward head element;
• in which the forward head element is positioned within the internal chamber of the plunger and the rear head element is positioned within the socket bore of the plunger.

A method of repositioning a plunger situated within a housing, the plunger having a longitudinal socket bore opening into an enlarged internal chamber, comprising:

• inserting a tool within the housing through a housing bore, the tool comprising:
• a pair of concentric and relatively rotatable shafts, comprising:
• an elongate and tubular outer shaft;
• and
• an elongate inner shaft;
• and
• a head assembly formed from adjacent coaxial head elements, comprising:
• a forward head element supported by the inner shaft, the forward head element closely but clearingly receivable within the socket bore;
• and
• a rear head element supported by the outer shaft and having the same cross-sectional profile and cross-sectional dimensions as the forward head element;
• positioning the forward head element within the internal chamber and the rear head element within the socket bore while the cross-sectional profiles of the head elements are aligned;
• relatively rotating the inner and outer shafts until the cross-sectional profiles of the head elements are in skewed opposition, thereby locking the plunger to the tool;
• and
• at least partially withdrawing the locked tool and plunger from the housing.