Restart WIFI just (!) setup

Hi there, i created a Musicplayer for my sun based on RPi3 and Volumio. A Webcam reads a QR Code that contains a playlist that Volumio plays via MPD. At home the Player is connected to the internet (even if mp3’s are local) but when we travel the destinations wifi is obviously new to Volumio. As i don´t have a keyboard not a hdmi connect it results in a offline mode if you like. My idea now is to use a GPIO button to call a script/command to just restart the initial WIFI Hotspot setup for Volumio. I would like to maintain all other settings, plugins etc and only (!) restart the wifi hotspot mode. Is there any script or command i can run for that? Thanks in advance for any hint!