I have read plenty of guides here and feel I really understand how to seduce women, but how much of it applies to a long-term relationship?

I've been dating my girlfriend for over 3 years now, and we've had a lot of ups and downs but we do genuinely love each other. I feel a lot of the issues stem from me naturally being a beta. I understand how to be an alpha male, but before I attempt it, I wanted to know if alpha-maling works once you already have such a long romantic history together.