i dont want to bust your bubble man, but expect to redo the fire ring setup every 10-15k miles, fire rings should only really be used in a competition only application, or where high boost sealing is needed. the rings themselves dont seem to hold up near as long as a properly done oring setup. i had a fire ring setup on my truck, and i have redone the setup 2 times, both times the rings failed, and cracked. the last time i went with a oring setup, becuase i dont see high boost, over 60psi, and dont use nitrous or water meth. if you are pulling the head, i would have it thouroughly checked, for flatness, the surface finish, and the ring grooves also, if one of the grooves is not cut right, that could be the cause right there, but the headgasket, and rings must go through the proper amount of heat cycles, and retorques to ensure that the rings are fully compressed. to do the repair, you will need a good engine hoist to lift the head off the block, good set of metric sockets, wrenches hand tools, lifting chain, a good set of feeler gauges. make sure that you have some moly grease for the arp studs, quality 3/8 &1/2" torque wrenches that are properly calibrated, I can't stress that enough, your dont want to over torquing, or under torquing the studs, and bolts you'll be installing. if you got access to a air compressor, and air tools, that will save time with dissasembly. some masking tape to cover openings that you dont want stuff to get into. it's not a really hard process, just take your time, make sure you mark wires taken off, and keep the valve train parts marked so that they go back in the same way taken out. if you have more questions, dont be afraid to ask!
Wes