When trying to install the Mod on the application original google play I get a "failed installation" error Given that I tried to directly install the mod, which didn't work for me either, then download the data, (2gb) then I renamed the OBB data to install the MOD without needing to download the 2gb and it didn't work either :( what could I do?
Platinmod's apks (both) cannot be installed over the playstore version, and vice versa.
1) Assuming you have the playstore version installed, what you should have done instead is to use the re-naming trick (entire com.klab.bleach folder) to uninstall the playstore version, install linking.apk, ignore the suspension warning, sign-in, quit, then patch mod.apk over linking.apk. If the re-naming trick is done properly, the remaining download is around 300mb++ and only done on mod.apk.
2) Anyway, since you are already stuck now. Why don't you just completely un-install everything and start over again? This time, install linking.apk straight away, sign in, then patch mod.apk over. Only start the 2gb install on mod.apk, since the suspension warning prevents you from proceeding further on linking.apk. It's only 25mins of your time, better than waste days getting stuck between legit and modded apks.
If you have a way to install back the playstore version, do it to double-check again that your game data is properly backed up to Klab ID. Then maybe you can try method (1) again :)