How to gunzip files recursively (or how to UNDO 'gzip -r')

You can use

gunzip -r Personal

which works the same as

gzip -d -r Personal

If gzip on your system does not have the -r option (e.g. busybox's gzip) , you can use

find Personal -name "*.gz" -type f -print0 | xargs -0 gunzip