This goes much easier if you have a bicycle work stand (I didn't).
NOTE: The bicycle I mounted this on had a welded piece of slotted metal on the port side lower frame (chain stay?) for the end of the coaster brake lever to attach to.
***A coaster brake bicycle that uses a band to secure the coaster brake lever may require a different method of mounting.
Initially, I used the enclosed rubber sleeve to cover the frame, lined everything up and test mounted the kick stand on the frame – Sliding the kick stand as far back as possible and snugged up the screws.
I scored the kick stand where the coaster brake mounting tab butted up against the kick stand on both sides of the tab.
I removed the kickstand and secured it in a bench vise.
Next, I used a hand file to make a slot for the coaster brake lever mounting tab to fit into.
I had the longer 305mm kick stand and had to shorten that to just under 280mm for a height proper fit.
For the final installation, I used a piece of automotive heater hose instead of the OEM rubber sleeve that came with the kick stand to cover the frame and a mini hose clamp to hold the hose in place.
I remounted the kick stand sliding it back so that the coaster brake lever tab fit into the slot. The slot / coaster brake lever tab combination keeps the kick stand from rotating.
I trimmed the hose and readjusted the hose clamp back against the kick stand; this holds the heater hose in place at the front and prevents the kick stand from sliding forward.
For my application, I cut a piece of 1/8” x 3/4” aluminum flat stock, rounded the corners, drilled two holes and used that to secure the kick stand to the frame.
It may not look pretty, but it does function quite well – ESPECIALLY when I’m loading groceries.