That was what I did.  I liked science fiction, so I began reading science fiction novels.  The first one took me something like a month to read and I barely understood it in the end.  But I kept going anyway.  The next one was even harder.  But I kept going anyway.  Eventually they became easier to read.  I was reading one a day by the end of that school year and I had gone from reading a few years behind to reading at the college level.  I had done it.  After all those years of passing as best I could, my tenth grade resource teacher helped me find the smart kid inside and I did what I had to do.