ok there is two ways to switch a bsp.
1 make a trigger volume called bsp 0,1. this would switch the bsp for all players if a player entered the trigger.
2 make a script

(script continuous switching
(if (= (unit_get_health biped1) 0)
(begin
(switch_bsp bsp 1)
)
)
)
(script continuous sync_part 
(if (= (unit_get_health biped1) 0)
(begin
(object_create_anew biped1)
(sleep 30)
)
)
)

This script uses a biped to make it sync over the net