pre_install() {
    # preparing module
    rmmod brcmfmac
}

post_install() {
    # restarting module after needed file installing
    modprobe brcmfmac
}

pre_upgrade() {
    # preparing module
    rmmod brcmfmac
}

post_upgrade() {
    # restarting module after needed file updating
    modprobe brcmfmac
}

pre_remove() {
    # since you don't need wi-fi, I guess I can remove module?
    rmmod brcmfmac
}

post_remove() {
    # enjoy your wi-fi-less device :D
    modprobe brcmfmac
}