Results of ct scan of left kidney: several large stones that may be difficult to pass. what is the likely next step.

Here are some ...: First, Doc and you will jointly decide if, when, and how to remove the "offending" stones. The options may be percutaneous nephrolithotripsy / ESWL or the procedures through the urethra to bladder upto ureter / kidney depending on the number, stone load, instrument / equipment availability, surgeon's proficiency, etc. So, ask Doc for detail...