How to design in Photoshop by using Bootstrap Grid?

Hello. I would like to help me with an idea, an answer please.. I want to create a psd design for a prestashop template using bootstrap, but, since I'm at the very begining of this "world", I dont' know how to do that.. I know that I can use bootstrap when implementing the template, but in design, in photoshop, how can I use it? I have used grid960 for another designs, but there is a special template for photoshop offered by the960grid pack, but at bootstrap, I don't know to be one such as this960grid.. Could anyone tell me how I should do? thank you all in advance.