Toyota Repair: 92 Camry v6 DOHC lower end knock, toyota engines, engine sounds

Question
was gong 70 and de-celereated suddenly then something poped.  Engine sounds like a machine gun RATTATATATATATAT.
Back middle cylinder has 30 LBS less pressure that the rest than the rest.
Theories?? Options?? Can I remove the rods and pistons from underneath or do i need to pull the engine.  Is there a source for Toyota engines of this vintage??

Answer
The rods and pistons come out through the top with the cylinder heads off, the loss of compression indicates a major mechanical problem,probably not worth trying to repair, try to locate a good used or remanufactured engine, they are plenty of suppliers online that would be glad to help.