The next step is to prepare one of the power terminals for the LED board by wrapping the leg of a resitor (chosen to match your LED's) around the end, as shown here:

You'll want this to be tight - needle nose pliers might help. Solder will also be used to help hold it in place. As shown below, you will also trim the legs of some resistors - hold on to those trimmings. One will be used as the other power terminal for this mini board (seen below). Trim the short leg of each LED and solder to the resistors, as shown. Make sure to put some heat-shrink tubing on the LED being soldered to the board here, there's no way to add it later.


Now, each bare leg of an LED goes into one of the holes along the top of the board (top being opposite to the two power terminals, and is also "up" on the pics above). Push the leg through so just a bit is showing on the side with the copper pads. Solder.
The other LED legs (the ones with resistors and heat shrink tubing) should now be soldered together at a common point. This would be to the resistor fastened to the board, but before the resistor itself, so that all resistors run in parallel.
Take another piece of snipped resistor leg, bend it in roughly in the middle. This piece will attach the other power terminal to the LED's exposed legs. This is done by soldering one end to the terminal, and then the bent piece should touch all the solder points we did earlier. Bad explanation, see pic below. This pic is of the first one I attempted. For the second one it was easier as the LED legs were lined up 4 in a row, unlike below. Please excuse the sloppy soldering job.

Above you can clearly see the power terminals. Don't worry at the moment about the orientation of the LED's - once installed you will orient them as needed. A good diagonal angle into the coin reject button seems to work well (YMMV). Below you see the first one installed, LED's oriented. Next to it are original bulbs (running at 5V, so dimmer than normal).

another view, power off

Another view of the finished result (well, the two blue ones installed, red are coming soon).

For the red, I will use 3 LED's instead of 4, as light gets through them better.
Hope this helps, or at least entertains.
If you'd like more into, clarification, more pics, or anything else, please ask.