Go to your Railworks folder on your harddrive, launch the utilities program. Then use the Packages Manager tab, clicking the install button and selecting your downloaded content you wish to install. Very simple.
Click the little blue box on the middle left window then go over to the right upper window box and go down to Great Northerner. Find the SD7 and check it off. You should be good to go.
Buzz 39 and holding. "Some people find fault like there's a reward for it."- Zig Ziglar "If you can dream it you can do it."- Walt Disney