yeah thats the point, i can not find my passphrases 
I would be extremely careful with removing the passphrase protected account if you can't remember the passphrase. Your only back up then is your second Ledger device in the safe deposit box. Are you 100% sure that it has the correct passphrase on it, is in good working order, hasn't been stolen, etc? Even something as simple as the software on it being out of date becomes a big risk if you have no other back ups of your passphrase. If you can't remember the passphrase and can't find your back ups, then you should set up a new passphrase, back it up properly, and send your coins one of the new addresses.I just tried on my Ledger Nano, which I use multiple passphrases on but always as a temporary passphrase and never as linked to a second PIN, and I was able to install Bitcoin, Ethereum, and Neo apps all at once. So it does seem that setting up a second PIN has decreased the storage available for on OP's device.
guys another question.. is that possible attached pinned 2nd account to set up as first account? 2nd pinned account have additional key as 25th keyword of passphrase, but i did not make it self usage. it has to be 2nd account right?
Yes. There is no way to set up a passphrase account as the primary account. You must first set up the primary account with the 24 word phrase it generates for you, and then specific your own passphrase for the 2nd (or 3rd, or 4th, etc.) account. 
