Hi Guys i want to remove lvl 8 skill restrictions to ride a wild horse in game just like how unicorns are set up .. please advise/help ..

This is a tunable value found in the GameplayData, in the RidingSkill XML.
You can easily tweak these values ingame using NRaas Retuner, but if you want to make your own tuning mod you can also open this package (found in the install directory of the game, under Game > Bin > Gameplay) and export the XML(s) you want in S3PE.

Just to add to what @CardinalSims said, NEVER mod the game bin packages! You must reinstall the game to fix anything you might mess up, if you cannot remember what to return the numbers to. As he says, export that xml, ITUN, or whatever you are modding to a new package, and make changes there. When you place your new package in the Packages folder, it will override the game file. That is basics of tuning mods.