Hyundai Repair: 2004 hyundai accent, head gasket failure, coolant hoses

Question
how do i change the head gasket on a 2004 hyundai accent???

Answer
You'll need to disconnect the exhuast, unhook the wire harness, fuel lines, vapor line, and coolant hoses, remove the timing belt, and remove the valve cover to access the head bolts.  

I have a couple concerns.  First, for someone who is familiar with working on cars, this is a pretty much straightforward disassembly and reassembly procedure.  The fact that you've asked this question leads me to suspect that it may be a more complicated task than you're ready to attempt on your own.  I'm not so much trying to discourage you from doing the job as to encourage you to have another more experienced person available as a mentor and guide.  

Second, the most typical reason for head gasket failure is overheating.  In those cases, the cylinder head is so warped that it needs to be replaced.  When you remove the cylinder head, you should have it checked for flatness.  If you don't have a precision straight edge, you should take it to a machine shop to have it checked.  The specification is either .002" or .003", depending on which engine you have.