how do i switch to the second disk of oddworld?

how do i switch to the second disk of oddworld abe's exodus? there are two disks for the playstation and im playing the first disk on the psp but this game wont let you save before switching disks is there another way for me to continue playing? if anyone has to know i have a 3.03oe-c

i haven't tried this but if i remember correctly you put the two parts into a folder and you dbl click on one of the parts and and you should get winRAR *it assumed its compressed* then you drag the archive iso or cso to wherever you want and supposedly it takes both parts and combines them into one

i don't know so don't hold it against me if it doesn't work i tried

ok i have now succesfully merged the two disks together and its playable but when i get to the part to where it asks me to switch disks it just stays at that screen