Removing a rib graft from bridge of my nose. I had a revision rhinoplasty done about 3 years ago.

Yes, the graft can be removed and then at the time of surgery a decision will be made to replace with a smaller graft or simply remove and that will be depend on the defect.  I have removed rib grafts in several patients with excellent outcomes but the dissection has to be very precise and should only be attempted by someone experienced in revision rhinoplasty. I would suggest consulting with more than one surgeon.

It is pretty common surgeons find rib grafting as a technical goal itself, and not as a mere tool to carve, sculpt and shape a well tailored piece matching the beauty of the nose, and this seems to be your unfortunate case.I strongly recommend you seek the help of a good and very creative revision rhinoplasty specialist, he will re-shape your dorsal graft or replace it by other brand new dorsum made by him.

Is the doctor not around for you to consult with? Even through the email? He might have the best insight into what is possible and how predictably it can be accomplished, because he did the last operation.Still, though, most likely a surgeon experienced in revision rhinoplasty could address this for you.Read the section in the "Learn more" link on how to stay out of trouble while searching for a rhinoplasty surgeon. Rhinoplasty is an exquisitely difficult operation to get right, and you should only have surgery if you are able to make yourself very confident in your surgeon's skills. 
I usually make computer morphs when I'm answering questions like this, to show the changes that are possible for a nose with a rhinoplasty, but of course you didn't post any photos. At the *very* bottom of the "Learn more" page is a link to instructions on taking and sending photos that are comprehensive and useful for an online consultation like this, in case you'd like a more complete evaluation.

You should be able to remove a dorsal graft without too much issue depending on the size of the graft. If it is a large graft or if it was used to cover underlying irregularities, it becomes a bit more complicated. Either way the graft can always be removed all together or re-sculpted and dramatically reduced in size if needed. I would search for some local revision rhinoplasty surgeons and see what they say after an in person evaluation. Best of luck