Fallout 4's mammoth high-resolution texture pack is now available to download through Steam as a free add-on. Provided you already own a copy of Fallout 4, you simply need to head to the Steam Store page for the texture pack and click install to add it to the game.
There are some things to note. Firstly, installing the high-resolution texture pack requires 58 GB of storage space on top of the 27 GB used by the base game (35 GB with the six expansions installed). Secondly, Bethesda lists the minimum system requirements as an Intel Core i7-5820HK processor, 8 GB of RAM, and an Nvidia GeForce GTX 1080 graphics card.
According to most who have tried out the high-res texture pack, you don't actually need such a beefy CPU or graphics card to smoothly run the upgraded textures. VRAM usage tends to fluctuate from 4 to 6 GB depending on your resolution with the texture pack enabled, an increase of a few GB on the original game.
Also, it's probably not worth downloading 58 GB of textures for Fallout 4 if you don't have a high-resolution monitor. The texture pack adds essentially no visual improvements for those with a 1080p monitor, and the difference is small at best on a 1440p display. On a 4K display you should notice increased sharpness and added detail across all objects and scenery in the Boston area.