Every big activity starts with something simple, an initiation ritual. For example, when you go to the gym, you dress in exercise clothing. If you want to run, you take running shoes.
This initiation ritual is the most important part of the activity. If you establish the ritual, over time you will be able to perform any activity you want.
The secret to establishing habits for difficult activities like going to the gym or studying hard is establishing simple habits that, over time, will get you to the more difficult activities. These simple habits should take less than two minutes and be easy to do. So instead of reading a chapter, read a page. Instead of doing a full workout, take your gym stuff and leave the house. Instead of running a marathon, wear running shoes.
Automate the entry habit, and you will automate the whole activity.