as requested here is a very simple tutorial on how to attach straps and tools and stuff you need:
explanation of the pics:
1. first pics shows the tools, dremel, screws(binding post with screw 3/16' x 1/2" bougth at home depot) ,leather straps , bottons. not shown glue and velcro
2. image 2 shows where you gonna drill the holes using the dremel, for reference I used a real nemrod holster (dont have the resin at hand). Also with the dremel you will drill holes on the leather straps.
3. image 3 shows how the strap will fit using the screws shown in image 1.
4. next image shows the other strap, for this straps no drilling is required you can attach both ends using velcro
5. then glue a button that you can buy at any hobby shop to give that real look to the strap.
this is how the straps will look on the holster after installed: