Rollcages and headliners

Im fine taking headliner out and doing the cage right, and making it easier for me. I have no experience putting in a headliner and do not know the difficulty level of it with or without a cage, so that is why I ask. The headliner is coming out no matter what, just didnt know if was smarter to wait to install the new one before of after cage install. What would be the lesser of the 2 evils? I can protect the headliner with welding blanket, aluminum sheet, card board, acrylic etc. if necessary but maybe it would be just as easy to install headliner afterwards.