I can see that many asked the same question at magentoforums but i don’t think this is satisfactorily answered there. I am not sure where could i find the solution and then tried to find out for myself. Here’s the outcome so far.
In the main product/view.phtml you would want to edit the options list. I myself wanted to play with the options listed on the page.
The file option is located here, where seonitik is name of template (for me as i worked on an existing project):
And those text and other fields are forged here:
I still have to find out what is the name of the process which uses these files to build the option list.
And i found it. It’s located here:
app/design/frontend/default/seonitik/template/catalog/product/view/options.phtml where seonitik is the name of template folder.