Users who make a donation via PayPal will receive a licence file which will allow the program to Substitute missing Assets, e.g. where the route author has used items from the IOW or Flora packages and you do not have them. This option also allows you to swap items you already have, e.g. replace trees with versions you prefer. You may also delete items entirely, e.g. gantries from electric routes.
Notice: If you have not received a licence within 24 hours, please email me direct. I have had a couple of licences bounced, mainly from U.S. ISPs, Comcast and AT&T in particular.