A multi-point exit door lock and method of installing same, the door lock including main lock and upper and lower lock modules. a push type panic bar, lock bolts associated with each of the lock modules, and a pull-type cable of predetermined length having its ends fixed to the main lock module and to each of the upper and lower lock modules, whereby pushing the panic bar opens all lock modules. The method of installing the new lock includes a template which is temporarily mounted to the exit door and rotated to successive positions for automatically and accurately marking all the drill holes for mounting all the lock modules at relative distances apart corresponding to the predetermined distances between them pre-established by the cables of predetermined length fixedly attached to the various lock modules.