How Do You Get Through a Tough Title?

I really enjoy reading new books and getting ARC and galley copies of books to review.  But what do you do when the book just seems impossible to get through.  I am reading one now and even though I am enjoying the story, the outline and some parts of it are just difficult to get through.  I want to give the book an honest review, and I want to finish it.  There have been very few books that I have started that I have not been able to finish.  I do not want to put this book in that category, because I want to know what is going to happen in the end.  So, how do you make it through the end of a book you want to know the ending to, but find it difficult to get through the story?  Do you move on to something else and come back to it later?  Do you just abandon it and review just what you have read.  I only have a couple more days before I have to submit my review, so giving up is not an option at this point.