The simplest way is to restore from a backup e.g from Time Machine
However if the last backup is long enough ago that there is other changes you want to keep the you can edit .bash_profile
In terminal
In a terminal you can use the full path to the editors ( /usr/bin/emacs /usr/bin/vi or /usr/bin/nano) to edit ~/.bash_profile
e.g.
/usr/bin/nano ~/.bash_profile
Or you could open it with the default text editor (by default TextEdit) via:
/usr/bin/open ~/.bash_profile
In GUI - from Dock or Finder
But also you can do this from TextEdit (or other GUI editors) by File->Open and go to your home directory. Depending on if you have set Finder to show all files or not show hidden ones (the default) you will either see .bash_profile in the list or you can hit ⌘ CMD+⇧ SHIFT+. which reveals hidden files in Open/Save dialogs. (the shortcut is from this answer)
PATH=$(getconf PATH)
, otherwise doPATH=/bin:/usr/bin
– glenn jackman Jun 22 '15 at 15:15PATH=$(/usr/bin/getconf PATH)
– fd0 Jun 22 '15 at 16:24