Loading Bootloader into P89V51RD2?

I have two P89V51RD2 microcontrollers, Out of this only one is working fine and in the other one the bootloader is corrupted. How can i replace the corrupted bootloader using working P89V51RD2.

Can i use MOSI, MISO & SCK pins of P89V51RD2 microcontroller ?

The only way I know is to use a parallel programmer I'm afraid.

PS I bet you weren't using a reset generator on the chip were you ??