You need to change complete firmware,because that FS is for branded phones and I recomend this:
MAIN:K810_R8BA024_MAIN_GENERIC_SM_RED53
FS:K810_R8BA024_FS_EUROPE_2_RED53 and that
CUSTPACK: HB1-06_Gen_CDA102568_11_R6A_GENERIC_EUROPE_2 (you already have that)