How to install Stock on S5 Active (G900A)?

Hello Guys,

the story is: i've just bought Galaxy S5 Active with some custom ROM installed (TMS5), rooted.
the version is 5.0: the kies is showing info like: G900FXXU1BOC7/G900AATT3BOC4/G870AUCU1BOC5/G900FXXU1BOC7 (ATT)

the problem: i'd really like to have stock firmware on this one? Can You please tell me what are the options for me?

Thanks,
Jazzhoo

Download from this link