you need firmware and USb drivers, but i gathered you already have that cause you managed to connect you phone to XS++. firmware: dont know what lanuguages you want, buti gather form the Uk hint...all you want is english? W850_R1JG001_FS_EUROPE_5_RED52 and W850_R1JG001_FS_S_E_EUROPE_RED52. just double check if you happy with those. also you can use any cust pack that is designed for the W850, so you can just use the default one on XS++ itself.