You can leave your current guild by going to the "Info" tab and tapping the three dots ("...") to the right of the guild TAG, and then tapping "Leave."
After this you can find and join guilds from the GUILDS tab, just as per usual.
You can leave your current guild by going to the "Info" tab and tapping the three dots ("...") to the right of the guild TAG, and then tapping "Leave."
After this you can find and join guilds from the GUILDS tab, just as per usual.