Ask bridesmaid to be new Moh?

I asked all of my friends to be bridesmaids/MOH a few months ago & everyone said yes. I choose my middle school friend to be my MOH even though she lives in Texas & our wedding is in Michigan. I was willing to work around the distance & anything else that may come up. Recently, my MOH told me that she felt she could not provide everything that a traditional MOH would do because of the distance & doesn’t not want to take away from my wedding day. We had a long talk about it & she’s right. I still asked her to be a bridesmaid but now i want another bridesmaid to be my new MOH. So my question is, how do I go about asking another bridesmaid to be my new MOH. It was hard for me to choose a MOH in the first place because it was a tie between 2 of my friends & just went with the friend I’ve known the longest for logical reasons. I’ve been overthinking my decision since I made it & now i feel this is a sign to choose the friend that should have been my MOH to begin with. I just want her to be excited & feel special without feeling like there was a bad reason i didn’t choose her first. I really regretted it & hope she understands i made a mistake.