Want to update my remote repository but I have no local one

Googleing this question find all the same answers:  use command line in local project to do merge or rebase.

I have simple problem:  I forked from a master into my personal github account many months ago but never got around to makeing a local.   My repository at github is many commits out of date.  It is not obvious how to update.  Surely there is a better way than deleteing my existing repository and doing another fork from the master.  I would think there is a way at github.com/myaccount to update github/myaccount/reallyoldjunk but looking for help all I see is complicated command line procedures on a local c:\localgitstuff\reallyoldjunk that I dont have.

[EDIT] gave up and deleted my repo and forked a new one.  I have a feeling that this is not the normal way to do things in the first place.