A commercially available kit for converting your home toilet to hands-free flushing will cost you $25 or more. If you have a 3d printer, the hack I detail in this log will cost you less than $10.
The mechanical connection to the toilet handle is a 3D printed hook plate attached with a wall hook adhesive strip. I got a little overzealous with 3D printing here. You could probably just use a wall hook with an adhesive strip. It took less than twenty minutes to 3D print at 30% infill and 0.6mm wall thickness.
The foot pedal is simply two 3D printed plates mounted on a hinge. Adhesive picture frame mounting strips are used to secure the bottom plate to the floor. A 3D printed loop (similar to the loop of the handle hook plate above) on the backside of the top pedal plate is used to connect the rope to the pedal. The pedal plates printed in less than two hours at 30% infill and 0.6mm wall thickness.
The only thing I may consider for the next revision is reducing the number of locations were dirt can accumulate so it's easier to clean and disinfect.