How to covert from existing ready website with AngularJS to Hybrid App

Hello Everyone,

I am very new to ionic framework and I have a question. If someone has already been asked this question, please forgive and point me to there.

How to covert from existing ready website which is done with AngularJS to Hybrid Ionic App. Shall I start from beginning or is there any suggestion to use the existing website.

Anything would be greatly appreciated!
Thanks