Eth from Boba L2 to L1

Hi, all I have just claimed my boba airdrop. Now, I have some eth left on Boba L2. I am trying to bridge eth to boba L1. How can I move the complete amount of Eth from L2 to L1? I don't think I can calculate gas fee and send the txn. I have already failed couple times by using "BRIDGE ALL" Any advise will be greatly appreciated.