Toyota Repair: blown head gasket, blown head gasket, radiator cap

Question
i think i have a blown head gasket in my 1990 toyota cressida.  it overheated for the first time last week, and my water keeps disappearing but there is no visible leaks.  can you give me any instructions on how to replace a blown head gasket in a toyota cressida?

thanks in advance any info you give me would be helpful as i'm not rich enough for the toyota places to fix it.  i already replaced the thermostat the other day and had the preasure checked in the radiator cap.  they said it was just fine.  my boyfriend thinks there may be water getting into the oil because it looks funny.

Answer
It is too involved of a repair for me to give step by step instructions, I recommend that you get a repair manual available at most autoparts stores it will have all the information you need, or try to find an independent repair shop that charges a lot less than the dealer.