How can I get POA over my stroke-survivor Dad when my narcissistic Mom has it?

My mom has POA and it is detrimental to his well-being.
I've only started learning in the last week about the abuse that was in my household due to my narcissistic mother. I do not know if my father is narcissistic; I suspect he is on her side though since it is his wife and I'm the only daughter, the one who followed in his professional footsteps, and am therefore a threat to my mother, though I never knew it before. My dad had his first stroke in 2006; since then he has had more things happen such as falls, trips to emergency rooms, and a seizure; they are not necessarily her fault but he was in her care when those things happened. In fact, his seizure happened when they traveled to Washington State last summer in 2014 and my mom did not pack my dad's CPAP machine which is prescribed to him & required of him to use; then he gets a seizure. Maybe it's a coincidence or not, but I was furious that she packed a car full of crap and did not bring his required medical equipment.

I have distanced myself a great deal from them in the past, not knowing why I didn't want to be around them and in spite of my strong love for my father; I was with him the first night he was in the hospital after the stroke; stayed up all night by his side so someone would be there; my mom had things to take care of understandably and I did not mind as it didn't cause problems with my work. I went to the majority of his rehab sessions & was there for his discharge, when my mother was hours late for the discharge; I remember my dad looking out over the railing outside asking where she was; heartbreaking to say the least.

My narcissistic mother has power of attorney over my father; should anything happen to her it is listed that myself & my two older brothers will have decision making power as to what becomes of him and his care. My two older brothers are busy with their lives & submit to my mother's thumb even though they don't agree; they just want to keep the peace, I get that. The thing is I want my father out of her custody as soon as possible because my mom is not helping him get better.

There's a lot of back story but what happened tonight is what has pushed me to the limit: my dad sat in a wet diaper for over 4 hours and my mom knew it was wet and didn't tell me so I could fix it. It's understandable for my father to forget but my mom -- the legal caretaker -- knew about it and says she forgot, thus she didn't tell me. A legal caretaker does not get to use an excuse like 'I forgot' because that is a sign that she should not be a caretaker. My professional background is in court reporting so I was exposed to lots of legal and medical matters over the years and have come to learn through experience when something is legally questionable.

Now that I am learning about narcissistic behavior traits I question if my mom really forgot or if she chose not to tell me, knowing that if I get upset at her she will get attention from me and that is all a narcissist wants -- attention for everything. She has used my father's sob story to fuel her narcissism all these years now & on top of it she blames me for problems because I get so upset with her poor treatment of him it often makes me walk away, giving them silent treatment, thus she tells everyone I'm not talking to them and I'm the one with the problem.

I love working with my father, doing therapies, doing all the stuff the therapists say he needs to do to get better; none of his therapists have ever said anything against what I do, they only encourage me. My mother has never been interested in that & has always held the mentality that that is the job of the therapists, not her. I always watch people work with him and ask lots of questions so I can learn how to do it; I have no problem changing his condom catheters or diapers; I told him not to apologize for it, since my mom makes him feel bad for it. I can handle poopy diapers; I cannot handle her poopy narcissistic attitude towards the situation, my father & life in general. It is not good for my father, myself, nor my mom, but she is in denial & refuses to see the reality of what she has brought on herself.

I don't want to lose my father more than I already have but am not sure what awaits me if I try to get power of attorney out of her narcissistic, overbearing, and controlling hands. Extended family is now learning about what's going on, namely my mom's older sister who knows my mom is in denial & it's not good what's going on here. I will be starting dialogue with my older brother (the other older brother is a half brother and not my mom's son) about what my concerns are. I'm the only one who fights her head on & it scares me to think what could become of it all. It kills me to think of leaving my dad in her care any longer & it scares me to think what the legal battle may entail.

If anyone else has experienced this or has advice on the power of attorney I would be more than grateful to hear from you.

Thank you.