Shopify expert with strong experience in Liquid

I have a client's Shopify store that needs product page customization.
1. Replace "Add to Cart" button into "Selection Lens"
2. Make a step-by-step order

I attached the workflow of the lens selection.

Please carefully read the workflow and write your strategy to implement this function.
Please don't hurry to submit the proposal quickly.

I am looking for the only expert who has the perfect solution for this project.

Thanks in advance,