How do I attach a pull up bar to this steel I bar?

[apacheDIYman]

I have this steel I bar in above my garage door, though I can only access one side of it as you can see in the photo:

http://imgur.com/dJxleTF

I want to attach a pull up bar, which can ideally take my body weight (up to 80kg). I have seen many brackets for steel I bars that you can fix a pull up bar to, but as I can only access half of this, is there a way I can wedge a pull up bar or some kind of clamp or bracket in, to then attach to the pull up bar to?

Any pull up bar will do, something like this that normally attaches to doors and often falls off!

https://www.google.co.uk/search?q=pull+up+bar&tbm=isch

 

[foxhole]

You could screw and glue a timber in the steel then fix you bar to that.