Horizon wont replace savegame.dat

I have already put up a similar post in another area which I realized was the wrong place to ask such a question, I’ve been trying to modify my main character in skyrim to get back a unique horse named shadowmere, I used horizon to extract the original savegame.dat and opened it in hex workshop to replace the refID of the purchaseable whiterun stables horse with the refID of shadowmere and saved as savegame.dat, however horizon is not replacing the original savegame.dat with the modded one, am I missing something or do I need my Xbox profile present too, any help would be appreciated

i cant l0ad Device-Explorer i forgot. Any link?? and or help? help 4 help?

man can ya answer

Also do I need a .dat unpacker?

what’s this?