There is some dust or dirt or other crud that has fallen down into the ramrod hole. There is a ramrod spring visible if you take off the barrel (not the trigger guard), but that's not blocking the ramrod, and it can only be removed by driving out a pin from one side of the forestock to the other - that will likely bust off a sliver of wood or make the hole for the pin enlarged - don't do it, it will not help.
Don't try to take anything apart. You'll end up buggering the screws up by trying to take things apart.
A professional repair guy will have long, long drill bits that will be 48 inches or so long, and a quick turn of that bit will loosen that junk.
If you want to try yourself, don't take anything apart. Draw the rod out. Whatever is down there will be easily loosened and fall out if you can get a long rod with some sort of screwdriver type flat blade on the bottom that can act as a scraper when it is at the bottom of the hole. I'm meaning a rod longer than the ramrod by six inches or so, that will fit down that ramrod channel / hole. If you have a flattened end, it will scrap that crud at the bottom of the hole when you rotate it.
Rotate the rod, scrape that crud loose, remove the rod, turn the musket barrel down, and tap with a rubber mallet (or just bounce the end of the musket barrel on carpeted floor,) and the dirt / dust / crud will fall out.
Some muskets were made so that the ramrod did extend a bit beyond the barrel - often the Lorenz rifles are this way.
Anyway, don't cut off part of the bottom end of the ramrod so shorten it! That happened to many a thousand muskets hanging over the mantle!