Advice needed

I want to ask for a separation/divorce as I am no longer happy and all roads to rekindling the love I felt have failed. I feel like I would rather do anything than to be at home or do anything with her.

Problem is I have never even broken up a casual relationship let alone asked to dissolve a marriage. How have you all done it? Is there anything to avoid doing when asking? Is there any particular way that works best? I’m scared to death and feel completely lost.

Thanks all