When you remember the greatness of Allah. When you remember that Allah has created all this universe which does not mean anything at the greatness of Allah and it is nothing compared to the greatness of Allah and I, as an individual I am nothing at all compared to this huge universe let alone compared to the greatest of Allah. When you pray in the middle of the night and you recollect or that is recall your sins, your shortcomings, the things they've done to others, the things that you have done to Allah Almighty and you feel how small and humiliated.. you are standing in front of Allah, you're praying and asking for forgiveness, you cannot help but to cry.
When you ask Allah for forgiveness, when you're prostrating or you are making Dua, if it comes from the heart, it rips your heart out because you know how bad you were and you still are and you don't know how Allah is going to conclude your life so you keep on praying, you keep on feeling this submissiveness and humility to Allah azza and you cannot help but to cry and that is why this is a little bit difficult.
It's bit difficult.. why? because you may try it for a year or two and nothing happens but if it does happen then you are among the fortunate ones, that is why you're encouraged to try and make it happen by faking it for few years, trying to convince yourself that you crying out of the fear of Allah and then Allah may bless you by making it and transforming it into sincere fear of Allah and crying so what's the benefit if I cry and tear falls from my eye?
The Prophet (pbuh) said; that there are two eyes.. would not see hell.. meaning if my eyes will not see hell then I would not be admitted to hell which means that definitely I will be in paradise. When one of them was an eye that remembered and tears came out of it so fearing Allah and crying out of this fear is a carte blanche that you will not enter hell and you will go to paradise with the grace of Allah so yes, if you can force yourself, if you can fake it and pretend that you are doing this out of the fear of Allah it would gradually turn into real and genuine fear of Allah.
May Allah grant all Muslims the strength to do what pleases Him (Ameen)