Hi all - first post so go easy I'm in the midst of an exterior tiling project, a redo of a bodge job. It's my front door threshold/step. I've removed the quarry tiles that were on there before and did my best to remove all of the adhesive (which I carefully chiselled for days). The issue I've got is the step itself isn't square - the tread is wider on the right than the left. I was hoping to be able to compensate with additional adhesive behind the riser tiles on the left but cannot do this as the new tiles won't provide enough overhang of the tread to allow me to tuck the riser tiles under on the right side where it's wider. I need a few more mil. So I need to determine the best way to slice the step back a bit on the right side by say 5mm to give breathing space. The main issue is the front face is quick set cement from a job in the past and rock solid. The riser is about 10cm high. I was thinking of using a diamond blade on an angle grinder by I won't get the depth I need. Been considering trying to chisel too, but will never get a nice flat face and with the hammer blows I worry I'll crack the hole step (which by the way is mostly very old mortar on brick. I suppose the right answer is a big concrete saw, but I'm trying to avoid buying new power tools. Appreciate any creative ideas.