Make out a timetable for the number of hours needed for study each day.
Add in a 10 to 15 mins break for every hour of study.
Devise a plan of what you are going to study for each day and get it done, no matter what.
Tick off the amount covered each day off the list. (The actual ticking off is important).
Breaks, plans and ticking off help the mind to concentrate and cope with the amount of time involved.
A little reward at the end of each day is also very helpful.
Keep the study regular and steady - no large amounts of study and then nothing for a long time. It's the steady flow and regular rhythm that helps.