Based on:https://www.youtube.com/watch?v=yCSW-LtYlJc&t=178s&ab_channel=GeneralWhine

Start

sudo apt-get update
sudo apt-get upgrade

Kernal Building

sudo apt install git bc bison flex libssl-dev make

// This will clone the kernel
git clone --depth=1 https://github.com/raspberrypi/linux

// This will configure the kernel
cd linux
KERNEL=kernel7l
make bcm2711_defconfig

// This will configure the driver
sed -ri "/CONFIG_SND_USB_POD/ { s/# (\w+).*/\1=m/; i CONFIG_SND_USB_LINE6=m
}" .config

// Build Kernel (takes a long time)
make -j4 zImage modules dtbs
sudo make modules_install
sudo cp arch/arm/boot/dts/*.dtb /boot/
sudo cp arch/arm/boot/dts/overlays/*.dtb* /boot/overlays/
sudo cp arch/arm/boot/dts/overlays/README /boot/overlays/
sudo cp arch/arm/boot/zImage /boot/$KERNEL.img

Wrap Up

sudo reboot

Plug in your pod, turn it on, and double check that everything works!