You should be able to rent one for cheap at one of your parts houses & ask them if they will but new blades in it before you walk out the door. Put a box end wrench on the center nut & pull the cutters toward you rather than pushing the blades into the cyl wall which means you need to change positions OFTEN as you go around the bore. Stop & check your work OFTEN, use WD40 & it will not cut evenly around the bore so stop when any section has ALMOST all of the ridge down flush, Just use your own judgement/patience/be conservative