Decisions like this can be hard as many live check by check and need everything they are earning. I think I would begin with having a one-on-one conversation with everyone and explaining the reasons why things are getting cut and how it is hard, but we would like to keep them which is why we're choosing to cut back hours. After this I would talk to everyone as a group and any concerns that come up can be discussed as a group as well. If it's possible within the organization, I would look for other ways to make up for the 10% cut of hours such as saving accounts.
a. Social proof
b. Commitment and consistency
c. Authority
d. Scarcity