Mount ISO to Drive , in this example D:

Change Drive letter if Appropriate and just run this command in CMD in Admin Mode.

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs 

Haven't tested on Windows 10, I think its part of Windows 10 and just needs to be enabled, but seemed with Windows 8.1 it would be downloaded, annoying because its a big file, and its on the ISO already. But if you test it on Windows 10 let me know if it works!

Download Full Package for offline use.