Hi, i will show you or well tell you how to download and install Halo 5 Forge without the store, reason? It doesn't show for everyone... aka me. Before we continue make sure to do the following...

1). Download Halo 5 Forge, Unsure about the link? look at the domain.

Direct link: goo.gl/2D5T4J
Torrent: https://mega.nz/#!y0BGwCLC!18IsLpSJO61TfZIeXLgZnyBGOmOkUdHDG0GttiKcJ6A

2). Make sure your OS is up to date (Im not 100% sure about previous versions)
3). Use that brain of yours, if you need coffee get it before we continue because this is vey basic stuff.

Now for the actual guide... this is real simple, follow it and go back if you do not understand.

1). CHANGE YOUR REGION TO US
2). Once installed move the file where you want, i just left it...
3). Open Windows Powershell as admin.
4). This is where it gets even easier... Type the following into Powershell

add-appxpackage D:\userfiles\Downloads\Microsoft.Halo5Forge_1.114.4592.2_x64_8wekyb3d8bbwe.EAppx
For you this may be a different directory... just point it to that directory... hit enter and it should look like this. (click to expand)

5). Go and get some more coffee while it's installing... and it should start looking like this... click me boi~~
6). Once the box has gone check that it has installed.
7). Run the game.... proof here i guess: http://i.imgur.com/DWOJdNU.jpg

EDIT: Some people are having issues downloading... i would highly suggest using https://www.internetdownloadmanager.com/
Just change region to US and open https://www.microsoft.com/en-us/store/p/halo-5-forge/9nblggh51mwp
EDIT GUIDE UPDATED!