How to get in Wonder Tower after explosion?

You enter the same way as you did the first time, i.e. go through Wonder City and take the elevator. You won't be able to access the topmost part of the tower, but there are no collectibles that far up. All trophies, riddles and breakable items are still reachable after completing the main campaign.

Once on the beam tht has a tight rope instead of just grappling and trying to use the vent (which is now blocked off) use grapnel boost from the beam, glide off the center pillar back out the door, curve right just a hair you will we the R1 symbol for a split second (literally it flashes at the top of screen so fast it's barely noticeable) hit it just right and u will grapnel to a ledge from there u can get to the gargoyles and o what ever