If I buy something online, can I change it in store for a size less?

If you can. As long as the piece and its respective size is available. Normally I buy online because sometimes there is no stock in the store. I don't know what your garment is in the store. But you can also change it online. You communicate with support and return the piece and they return it to you with the other measure.

Exact cris molina

And

Thanks, I'll go check ... 🙏