@rewrew If you are using SuperSU in v7.5, I recommend starting from scratch anyway. If you are using MagiskSU in v7.5, delete LG Health from system/priv-app/LGMyWellness if installed and delete SmartWorld from system/priv-app/LGSmartWorld if installed. To do this, you can use a file manager with root explorer capabilities (such as Amaze, which is free). After completing these steps, dirty-flash the v7.6 update on top of v7.5. It probably will work, but do NOT hold me responsible if anything goes wrong. Good luck!