Build a good connection with her - don't just talk about the usual shit like "how's work?", talk about whatever you like and build upon things that you have in common. But most importantly of all, be chilled out and have the brass balls to talk about whatever you like.

Secondly, state your interest in her to let her know you like her. It can be something as simple as "you're really fun to hang out with" or "I've always thought you're really pretty". Say it in a way that doesn't necessitate a response, more in a way of "I'm giving you value, so you must be quite cool".

Hope this helps dude. Post a field report if it goes well!