i have a 1990 civic hatch with a 96 civic motor ( d16y7 ) and i was tightening down the bolts on the valve cover and one of the broke off whats the best way to get the broken bolt out .

 

take the valve cover off, and unbolt it.

did you even look?

 

Lucky for you that threaded section is very tiny. Take the valve cover off and it's a stud that threads into the head or cam assembly.

Comes out easily.
Buy it at the dealer, it's not expensive and a junkyard will not be worth the hassle for it.
TQ spec for that crown bolt is 7-8 ft. lbs.
If your valve cover leaks, buy a new gasket.

 

lol I've done that nearly 19 years ago, the little metal washer fell off and I didn't notice, so the bolt bottomed out before the head even touched the rubber grommet part... and snap, it broke! that was my first valve adjustment on my brand new 98 civic