Oh man-- good luck.
Doing some family of origin work with my therapist has gone a long way to help me combat passive aggressive tendencies. I came to see that my family's communication system growing up didn't make space to freely/safely express feelings (especially negative)-- so I had to find alternate ways to express my anger, frustration, fear, loneliness, etc. This is the root of my passive aggressiveness-- and understanding the root helped open up my mind to ways in which it manifests as an adult.
For instance at work I don't feel allowed to ask for more guidance or help on my projects (in other words, "express my fear"), so I tend to procrastinate and let things get chaotic… when things get chaotic I'm allowed to express how I feel, but only because things have gotten desperate and out of hand at that point and the "normal" rules don't apply. In a way, I need things to get chaotic so that I can eventually be heard. This is a pattern I repeat again and again.
My work example probably isn't helpful for your situation, but I tell it because based on my limited experience passive-aggressive tendencies manifest differently for everyone. So, I think the best way to avoid being passive aggressive is to understand where the root of the personality disorder exists within you-- if youre like me, this will allow you to bring a gentle awareness of your adult tendencies so that you can start to notice your own patterns.
My only "easy" advice would be to try to be direct as possible in the way you communicate to your spouse-- even if it comes at the risk of offending or upsetting her. It couldn't hurt to let her know that many times you're too scared to be direct with her because of the way you were taught to communicate in your family… and then you could ask for forgiveness in advance for your bluntness, because you are NOT going to be good at communicating directly if you've relied on passive-agreesiveness for decades.
“When we disclose the thought and intents of our hearts in surrender, we identify with one another at depth.”