Add a datepicker to product customization field

[OnixV]

Hello, 

I need for my shop a datepicker in the customization field so that the customer can choose a specific date for the product. I think the easiest way would be to implement a jquery ui datepicker to product.tpl / product-controller.tpl / product-customization.tpl but I don't know how to proceed. I work on prestashop 1.7.6.1 and unfortunately I haven't found any tutorial for 1.7. 

Could you please help me or redirect me to a documentation / tutorial ?

Thank you for your answers !