You must use these files:
C510_R1FA035_MAIN_GENERIC_KT_RED53
C510_R1FA035_FS_APAC-ANZ_RED53
K850i_1201-0102_R11A_GENERIC_APAC-ANZ (K850 custpack is same with C510 custpack)
After flashing update via
SEUS.
OR
With
A2uploader click
File System Tool and
drag & drop:
customize_upgrade.xml to
TPA > PRESET > CUSTOM
Download:
C510 customize_upgrade APAC-ANZ.rar
Then turn on phone and when you see "Please wait" ... again turn off and update via
SEUS.