How do you update PSP from 3.10 to 3.90?

if you have a PSP 1000/2000 ta-088 or lower mainboards u can use a pandora's battery. as long your psp mainboard is ta-088 v2 or lower. u can't use on the psp 2000 ta-088 v3 or psp 3000 otherwise your psp is bricked.