Jot down every idea that comes to you in a notebook and carry this notebook with you everywhere, even the bathroom. Part of the magic of writing a novel is that inspiration begins to hit you when you least expect it, so be prepared. You may fully well believe with all confidence that you are going to remember any really great ideas, but you won't. Worse yet, you'll waste precious time struggling to remember. If it's written down, you avoid both these obstructions to completing your novel.
Set a daily writing goal and don't let anything stop you from meeting it. Sixty days is probably not enough time to complete an 800-page epic, so be realistic about how many words you can honestly produce in an average day. A 300-page novel means five pages a day, every single day. If you know this is unrealistic, then set a goal of writing a 250-page novel, or give yourself more time to complete your novel. By boiling down the entire novel into pages per day, you get the psychological edge of waking up every day not thinking about how many pages you have to go before you're finished, but only about putting out a certain number of pages that day.
Create as detailed an outline or summary of your story as possible. Don't assume you have to use the outline format that gave you so much trouble in English classes; toss out the I. and II. and A. and B. if that kind of outline doesn't work for you, write out in two to five pages as much of the story as you know you've got in your head. Then add as many pages as it takes to draw up character profiles, giving them names, descriptions, importance to plot, and even a list of quotes that the other characters would use to describe them.
Make writing the first thing you do with any spare time every day. Even the most talented writers can have trouble completing a novel in two months, because they don't have the discipline to make writing the single most important part of their day. You may have a job, or you may be going to school, or you may be taking care of a family; but if you really expect to complete a novel in sixty days, you have to commit to finding the time to write every single day.
Dedicate yourself to a seven-day work week every week of those sixty days. There are going to be any number of distractions, and certainly things will come up that may be obstacles to achieving this goal. Just remember that every minute spent watching TV or checking your email or talking on the phone with friends is a minute that you aren't writing. Writing a novel is tough enough without a deadline. If you want to write in sixty days, you have to rise to the occasion and commit to writing when you could be relaxing.
Delay every routine task that can be accomplished later until after you have produced some words. Any task that is not an emergency can be delayed, and you won't be any worse off for it. In addition, make it easier on yourself to do away with routine tasks. Plan a menu ahead of time, so that you don't waste time deciding what to eat and cooking something too time-consuming. Plan ahead: A few days before you sit down to write, examine your everyday tasks, and figure out a temporary way to reduce them, or better yet, eliminate them.