Everone has their own best methods, but I have always used a Dremmel with a steel sawblade. Follow up with a sandwheel to even it up. The HL and Tamiya Pershing is a Korean War (late production) model so you may want to fold up the 2 center sand skirts for MG ammo stowage and discard the front and rear sections. they were hinge mounted and could be folded up for track work. The skirts were a real pain in the butt and most were simply removed and tossed. The Marines came up with the idea of using them to carry extra MG ammo boxes. (Direly needed facing thousands of Chinese in mass charges.) I have included a coupleshots plus a local M-46 with original sand skirts to show the bolt positions.(same chassis) When the skirts are off, be sure to add the bolt holes. If you leave them on, at least "weld" a bar or cables to hold the ammo boxes in place on the fenders where HL put them. Some Pershings in WW II left the skirts on, but they never entered the war until April 1945, only 6 months before the end. Between WW II and korea, crews had time to learn of the disadvantages of the skirts and once they left the "pristine" training environment of stateside, off they came.