FYI: If your installing a Kahler FIXED BASS BRIDGE where a Fender style standard bass bridge was (the ones with the 4 or 5 inline holes at left), you will not have to do anything but reuse the same old holes to mount the new bridge. No modifications are necessary. Otherwise...

There is no template for a fixed bass bridge. none is needed really if you follow some simple rules.

1) Mark out the intonation line on the bass top.

2) Your trying to get the exact center of the bridge area. To find the centerline for the bridge you can use the dots on the neck as a guide using a long yardstick. Make a mark across the intonation line.  Once this line and the previously drawn intonation line is established and intersecting each other..., the "+" marks the "centered/ intonation" sweet spot)...

Mount the bridge using the plate holes right over the intonation line and using the 2 inside screws to centerline the bridge in the center.

The pre-setup of the fixed bridge:

1) Make sure the head of each allen adjuster in the back of each saddle is flush with the surface.

2) Loosen the two allen set screws on each saddle so they slide in four directions. Note the travel distance and position them all equally about 2/3rds of the way forward (that would be sliding them downward abit further as seen in the picture) and move the two outboard saddles all the way to the edge. Tighten all the saddles gently and without force until they are barely snug. At this point all the saddles are semi snug and can move in 4 directions if moderately forced. Try to keep them from covering any mounting holes in the plate so you can mark the body top using the holes as a guide. (FYI: the ball end of string goes in the open end of the saddle at the top in the picture).

3) Mark out the screw holes using the mounting plate. The two outboard saddles should be clear of the outboard mounting holes so you can mark them easily enough at this point. Next, you can jockey around the inner saddles to mark the inner holes. Once marked, mount the bridge using the provided wood screws. Now re loosen all the saddles and spread them out equally leaving a quarter inch or so of space on the outsides.

You can intonate from this point.