Changing the 'Product Block' from a drop down menu to a nice radio button just like the 'Add to bad' button.

Hi everyone, 

https://www.peaultd.com/argan-oil

On my custom product page, I want to change the sizing of the product from a drop down of 30ml and 100ml to a radio button that looks like the 'Add to bag' button I already have. Let me know if this is possible please.