cant say i have done those tires. but i have a hot knife with diffrent bits. and its not to bad to cut them up. let the unit get nice and hot and use the heat to do the work on those hard rubber tires.
i have both 1/8 and 1/4 blade heads. i use my 1/8 for tsl swampers up to 38 with the skinny wear bars. 1/4 blade head for 38.5 and up swampers with fat wear bars. so if you want some good width i might use 1/4 blade. i would go round cut blades for tires with lots of tread. and if half gone and just cuttin wear bars out square heads blades.
second half of page 35 is the ideal tire hot knife. i have the 42836. this company will sell to public if i recall. if not pm me and i can get it for ya if you need one. i have a account threw them.
http://www.myerstiresupply.com/pdfcatalog/PDFs/Final_Finish.pdf