valve cover bolt ??? & help....

[rodstored-72]

all,
well i was going to fire her up last night & go for a quick spin & luckily i thought that i better look under the hood & make sure everything is ok! (it had been a few weeks since i drove her) well i did & i found atleast 2 valve cover bolts were broke off!! now i need to use a extractor (?) & get the broke bolts out of the cylinder head!!! (insert bad words here). the bolts were arp allen head bolts that allow the nut to slip over them & tighten from down. my heads are dart iron eagle II. it is a 383 bore. i have billet valve covers (smooth) i am wondering if any of you guys ever had a similar situation & what exactly you did to fix it?? & also if you guys can give me some helpful do's & dont's???

thanks for any input & guidance...

rodstored-72