Okay so im new here and dont have heavy mechanic experience. But I was changing my spark plugs todayand when I was putting my balance tube back on two of the bolts stripped.. one of them the bolt snapped off and its still in the hole. How does one go about fixing this? How much will it cost?

 

You can use an "easy out" tool, but it can be a bit tricky, so you need to take your time. 1st you must drill a small hole into the broken off bolt, then insert the tool, which is reverse threads, it will bite into the hole and hopefully extract it. heres a link to something you will be looking for.Irwin 53535 5 pc Easy Out Screw Extractor Set

Found a utube video

 

Use an anti Seize compound when re-installing the bolts, when you have dis-similar metals they can seize up, a combination of galvanic corrosion and the heating and cooling of these two different metals can cause them to get a pretty tight grip on each other. Always use anti seize compound when you work on aluminum parts like intake manifolds etc.
Also, be careful when you are drilling out the old bolts, cover any open holes that shavings might drop into ,plug them with a shop rag, paper towel or masking/duct tape . And don't over tighten when you do finish putting it back together. You might consider getting yourself a torque wrench too, but not completely necessary.