how do you fit headgasket seals? (if that is the right term for them)

Hello Maitana2-- Your are talking about a major repair job on your 1992 Mazda MX-6. By asking this question I would have to surmise that you are not a well trained mechanic. Therefore I suggest you take your car to someone who is. If you must do this job yourself, buy yourself a manual, like Chiltons, and get the tools you will need. I hope you appreciate my advice. It will save you a severe headache. Good luck from Bovan.