Google Play Music remove pinned offline music quicker When starting with the Google Music (or Play Music) app I've selected quite a few albums for offline syncing over time. Is there a way to quickly get an overview of my offline music and remove it?

When having the "offline music" view filter on I see tons of songs that I've to deselect one-by-one and I don't seem to find out how to do a multiple select or any other way to speed up this proces.
If you use a file manager, you can browse to /mnt/sdcard/Android/data/com.google.android.music/cache/music and just delete everything you want from there.