It's hard to say there's a best way to address quotes like this a whole bunch is tied up in your goals for using a particular quote in a particular piece. What you can work towards, though, is giving the reader as much information as possible to understand the context of the person's words. I would advocate against presenting a rewritten quote without providing the original.

In books I've come across about education of Black adults and children before and during the Civil War, I've seen a number of texts where the author provides an original quote in a footnote attached to a summary or context. My read of the quote you shared is something related to enslaved people taking a stand on an issue so you could make a general summary statement about the quote and put the full, original quote in a footnote. As an example, Stephanie E. Jones-Rogers liberally uses direct quotes in the footnotes of her book, They Were Her Property.

One thing that Jones-Rogers explains is that most of her quotes come from WPA interviews. She consistently provides context for the interview and in virtually every case, describes the interviewers race, gender, and place of origin when she knew it. For example, if a WPA interviewer was a Black man born and raised in Mississippi after the Civil War talking to an elderly formerly enslaved man living in Mississippi, the annotation of a quote like you've described reads differently than if the interviewer were a white man from Maine. This isn't to say it's our call to judge how well the interviewer did or did not capture the interviewee's words, but rather it gives the reader information to situate the quote in time and space.

Another approach is to simply include the quote as originally transcribed with a footnote citation to the source with no modification at all. In this example, Heather Andrea Williams sets up the quote and then let the woman's words speak for themselves. I did find one of two example where an author included an original quote with a word in brackets to explain a particularly obscure word or term. Your example quote, though, doesn't include anything like that. (I'm assuming you've explained what "buttons" the person is talking about elsewhere in the piece.)

I also wanted to pass along two resources. First, this new project, the Inclusive Historian's Handbook is working through a variety of issues related to writing about and thinking about history and although they haven't touched upon your particular question yet, the articles are interesting reads. Second, if it hasn't crossed your radar, the Sojourner Truth Project is a student project and worth reading. She walks through the tensions around changing enslaved or previously enslaved people's words and provides lots of things to consider.