How to clean up overlay2 folder when docker doesn't start up

In my application the docker is not running due to no space availability. The docker overlay2 folder is using the majority of the disk space. I tried starting docker in debug mode but it throws error as “Failed to start daemon: error while opening volume store metadata database: timeout” issue. I couldn’t use “docker prune -a” command since my docker is not starting .

Could anyone suggest me a way to clean overlay2 folder or any suggestion to free up some space.