Regardless of the type of block you will be mounting on your model ship, you need to clear the holes using a small drill bit and deepen the grooves running along the sides of the block using a file.
Using the grooves of the block, wrap a piece of line tightly around the block, tie with one knot to create a loop and apply one drop of rigging glue. Let dry then take a thinner line and tie this around the two ends of the line looped around the block. This thinner line should be wrapped three to six times around the looped line. Again, tie one knot and glue in place.
In order to mount the block to your model ship, insert an eye pin or eyebolt into your model and tie the block assembly loop to this fitting.
You are now ready to thread a line from the block to the part of your ship model you are working on. To make your life easier, dip both ends of the long line into wood glue. Once dried, cut the ends on an angle. This will stiffen the ends making it easy to insert the line through the holes of the block.