To forcefully do something you're not supposed to do
Perhaps:
To act in a devil-may-care manner.
a very casual attitude; a worry free or carefree attitude
To act in a like a bull in a china shop
Cambridge Advanced Learner's Dictionary - Page 181 2008 - like a bull in a china shop If someone is like a bull in a china shop, they are very careless in the way that they move or behave
More:
go for broke
letting it fly
reckless
taking a chance
try to crash through the soup
shoot the works
hazard all
plunge
take a flier
(both of finance) speculate, sell short
go out on a limb
play fast and loose
stick one's neck out
take a shot (or stab) in the dark
tempt fate (or fortune)
trust to chance
"You cannot just do whatever you want. You must obey the rules".
or,
"You cannot just throw caution to the wind.
or,
"We couldn't find any player for the concert, so he just improvised.
It sounds like you're talking about brute force. A steamroller might convey the appropriate imagery.
He is like a steamroller; nothing will stop him from getting work done.
Someone who acts carelessly this way may do so with reckless abandon.
Isn't the verb force enough?
- You forced a pin into the plug and deformed it in the process
- There is a traffic jam ahead. You forced your way to a different lane to continue the journey. There is enough space, but the markings on the road say you cannot switch lanes there.
- Someone asks you to perform a difficult piece at a concert. You forced yourself to perform despite being well aware that the piece is beyond your ability, hoping that perhaps you have practiced hard enough and the audience will not observe this
You cannot force it. You must obey the rules.
We couldn't find any player for the concert, so he just forced himself to do it.