you missed some parts:
piccolo dies officially in the bebi saga, because bebi wishes for the planet tugul, the black dragonballs are respread across the universe, but this time they couldnt collect them, after killing bebi, they moved everyone to tugul until earth could be restored. but before the planet blows up, goku IT's back to save a kid, piccolo helps him and pretends to IT back with him, goku couldnt return beacue he overused IT, and piccolo has a cool speech to gohan telepathicly about how if he dies, the black star dragonballs cannot be used again, and he wishs that the evil cannot be redone and you see the countdown above him, and his arm starts to burn off, then loads of magma and stuff blows him apart then the planet goes boom, thats how piccolo dies ^_^
how evil shenron dies is once he stops the huge blast, he supposeivly dies, vegeta trys to kill shenron again and gets spikes shoved though his arm, and his left to die, shenron start to destroy the universe with him evil ki, but suddenly, goku rises out of the huge crater with a huge spirit bomb, and shenron cacks himself, and trys to block and dies a typical ending..aww...then the dragon appears and goku wishes that all the planets problems to be cleaned and all the who died (all of the humans) to be ressurected, then the dragon says " it is time" and goku says, "already?" and they fly off, but before that, he whispers somthing to vegeta and takes off, meets krillin and spars and looses, then meets piccolo and says thanks for everything, and dissipears *rah*