Cleanup a git repository of unwanted files/history

gistfile1.txt

# List all large blobs in a git repository sorted by blob size in descending order.
git rev-list --objects master | git cat-file --batch-check='%(objectsize) %(objecttype) %(objectname) %(rest)' | sort -k1,1 -rn > ~/Desktop/abc.txt

# Rewrite history removing history of a file
git filter-branch --force --index-filter \
'git rm --cached --ignore-unmatch <path/to/unwanted/file>' \
--prune-empty --tag-name-filter cat -- --all