I expect that you will have to push a needle through the silicone and then pull the wick through. You may have to purchase a long needle or use some long nose pliers to grab the point of the needle.
Les is correct. If you don't have a wicking needle (which is extremely long), you'll need to use whatever is the longest needle you have and a pair of pliers. Do your best to center the needle hole in the tip, especially when wicking the mold for the first time, so that your wicks aren't off-center.
Maybe a long upholstery type needle will work Les?
An upholstery needle would probably be a good substitute for a wicking needle.
I assumed that i would use a bobby pin or something similar to hold the bottom end of the wick in the center and pour the wax into the holes.
That's what I use.