/usr and /var folder consumes too much space

/usr shows 5.6G
/var shows 1.5G
now suggest me what should i do?
how to clean up those folder and which file should i remove,
also mention the command to remove those files.
how to deep dive into usr and var folder?
Thanks in advance:)

check mysql configuration file and see if there is log-bin enabled. log-bin uses a lot storage space and that maybe the cause.