How do I clean a tank without harming the shrimp?

Hello!

I have a betta tank that also has shrimp (a fluval flex 15 gallon). It's planted, but a few of the plants have moved from where I want them to be and the moss that was on a piece of wood has become detached and some things have moved around from where I want them to be. I'd really like to be able to empty out the tank, clean everything, and arrange it properly again, but I'm afraid that I will harm the shrimp if I try to do it. I'd try to catch as many as I could, but there are a lot of hiding spots for them and there are quite a few babies. I'm worried I'd end up harming them when trying to catch them, or if I didn't see them before I take things out.

I don't have a gravel vac and mostly depend on a snail and scrubbing by hand to handle algae buildup and the filter (which I do clean weekly) for cleanup, but I feel like there's probably a lot of mess in the substrate as well that needs to be cleaned out as well. I just don't want to hurt the little ones!