string into the upper stator 70 to drive the rotor within the stator 70 the flow of liquid acting downwards against the helical shaped shaft of the rotor causes the rotor to rotate within the upper stator 70 which in turn causes rotation of the concentric shaft of the rotor which extends from the helically shaped portion of the rotor to the drive end 74 and hence rotation of the casing cutter 76 the cutting blades 77 are moved to the cutting position shown in fig2 by means of the liquid flow within the cutting retrieving tool typically the liquid used to drive the rotor of the mud motor and to extend the cutting blades 77 of the casing cutter 76 is water and where the cutting and retrieval tool is used offshore then the liquid is preferably seawater however other liquids such as drilling mud could be used fig4 shows the wellhead removal tool 2 in more detail the tool 2 has three engagement arms 3 only two shown the engagement arms 3 attach on to an external profile 4 of the wellhead 1 the engagement arms 3 are mounted in a protective skirt 5 by means of a pivot 6 the pivot 6 enables the engagement arms 3 to pivot from an engaged position where they engage the wellhead 1 to a disengaged position the engagement arms 3 are biased towards the disengaged position by means of helical springs 50 only one shown mounted on top of the protective skirt 5 and above the engagement arms 3 there is an upper housing 7 the skirt 5 is bolted to the upper housing 7 by bolts 56.