You blanche them and bread them & then freeze them, just like the ones you find in the grocery store, ready to take out of the package and drop in hot oil for frying !!
How To Freeze Squash So It Don't Thaw Mushy?
The only way to freeze squash and not get a mushy mess when thawed is to freeze dry it! It can be done, but you need quite a bit of equipment, liquid nitrogen (dry Ice), a good container and a really thick strong pair of gloves. Drop the squash in the container and it freezes instantly and reconstitutes fine.