In a small garden you may never fill your bin. The contents will sink as they break down. You can remove finished compost from the hatch at the bottom, leaving the upper layers to mature.
Or ...leave the 'full' bin to finish composting, and start filling a second bin! A lot of people will have a bin 'on the go' - being filled with new material while a second bin is
rested and left to make compost. When the compost is ready it can be used. Then swap over - start filling the empty bin and leave the one you have been filling to
make more compost.
Or…. carefully lift the bin off the heap, and cover it with an old piece of carpet or sacking (weighted down to stop it blowing around).
Start filling the bin again, adding some of the partly composted layer to get things going again.