how to get the stash back after pulling

Just use git stash pop or git stash apply. As long as the stashed changes do not conflict with what you pulled or edited, it will just work, if not you get some merge conflicts that you can resolve like when you do a merge or rebase.

$ git stash list            # see stash list(s) 
$ git stash apply           # default take the top one 'stash@{0}'
$ git stash pop             # pop = apply + drop, take the top stash changes then  delete it  

$ git stash apply stash@{1} # get back number 2 stash changes