First, you’ll need to establish a centre-line for your track. You can do this by marking a cork sub-roadbed. Check the cork to see if it’s smooth and free of bumps and lumps -- for a smooth base.
Second, you will need to use a silicone sealant (or equivalent) to lay the cork roadbed in place. Then staple the cork roadbed down with track nails to hold it firmly in place as the sealant dries. But don’t drive the track nails all the way through the cork. As you will have to remove the nails once the sealant dries.
Once the cork roadbed is in place, you can continue with laying the track and spreading the ballast. Installing a cork roadbed is relatively easy and does not require a lot of tools or materials.