A lot of content of XBOX supporting mods but nothing on how it is done. Is this a feature not available yet??

Not yet, won't be till the new year when the GECK gets released to PC to start making the ones than can be used on the consoles.

The mods available now are pretty basic compared to what will be possible with the GECK.

It's going to be quite awhile before mods are avialable on Xbox or PS4.

So far, what's on PC is very limited because the GECK has not been released yet. Bethesda will be releasing that early next year.

Now i just need to wait for a mod so i can have a mutant hound replace dogmeat lol