If you’d like to clear your downloads on your current device, you can do that in one tap! No worries, you can always download your music back again by using the Sync Downloads setting.
On Android, tap the Menu button on the top left-hand side of your screen, go to Settings > Clear Downloads.
On iOS, tap the My Music icon in the bottom right-hand corner > Settings wheel in the top left-hand corner > Pro Options > Clear Downloads.