Your talking about when you go back as Ratchet. So........... (I am doing this all from my mind, so it won't be 100% right.)
Jump onto the platform with the boxes on it, get whats in the boxes then jump out as far as you can, use the truster to glide down to the ground. It might take a few tries to do it.
Then you take out a force field (its the glowing globe thingy, its not a swing thingy). You meet some dumb ass birds, take 'em out. You then go across two, or three platfroms, that will sink if you stand on them to long. More dumbass crabs, with another force field. Up ahead will be a vendor, if you die you will restart here.
When you get to the vendor you can go left or right:
Left: takes you so you can unlock what you did as Clank, what really comes in handy is that you can buy health upgrades from a machine, (5,000 bolts adds one live hit, and 35,000 adds three more (8 total), I think thats the prices).
Right: Takes you to the info bot, buts thats not easy. When you get close to it, it moves away from you, you chase the thing to the end of the level.
If that doesn't help check out the faqs in the link CPUWIZ posted. IMO, I think ZoopSoul has the best one, thats the one I used for the gold bolts.