*scratch*.el

(progn
  (local-unset-key (kbd "M-/"))
  (global-set-key  (kbd "M-/") 'dabbrev-expand)
  (describe-key-briefly (kbd "M-/")))
M-/ runs the command hippie-expand"M-/ runs the command hippie-expand"
(pp-to-string
 (let (wot)
   (map-keymap (lambda (a b) (add-to-list 'wot (cons a b))) global-map)
   wot))
"(
  (switch-frame . handle-switch-frame)
  (select-window . handle-select-window)
  (delete-frame . handle-delete-frame)
...
  (remap keymap
         (find-file-other-window)
         (find-file)
         (dabbrev-expand . hippie-expand))
)
"

(setf (cdr (assoc 'remap global-map)) '(keymap (find-file-other-window) (find-file)))

(keymap (find-file-other-window) (find-file))