Translation:I change my clothes.
I don't believe éadaí by itself is correct. Ó Dónaill gives "to change clothes" as éadach a athrú, with éadach in the singular. I've also found several examples of do chuid éadaigh/éadaí a chur ort for "to get dressed" so it's possible that'd work too. So this should either be athraím mo chuid éadaigh (more traditional) or athraím mo chuid éadaí
So I went to this discussion to say, hurray, for once Duolingo gives us a useful sentence, unlike "do you close the wine?" and "we grow when we run," and then I read earlier comments which indicate that Duolingo's Irish translation of "I change my clothes" is "weird" and unusual. Sigh. I'm beginning to think that maybe you get what you pay for...