Hi, thanks for downloading my pack!
To install this, as long as you have the Bedrock RTX beta, all that should be necessary is double clicking the "TheCivilHulk RTX 64X64.mcpack" file. This should load it into your game, and during world creation, or in the settings of an existing world, you should be able to activate it from the "my packs" section. If you have any issues with this, feel free to message me on reddit u/TheCivilHulk, or on the discord for r/MinecraftRTX.