Hi dolebopper,
We recommend that you follow the steps in the link below to save space on your computer by moving your iTunes library to an external hard drive.
Move your iTunes library to another computer - Apple Support
To perform the recommended troubleshooting steps via the link above, complete the steps in the sections titled "Consolidate your files in the iTunes folder" and "Back up your library and media files."
Consolidate your files in the iTunes folder
You can consolidate all the files in your library in the iTunes folder to make it easier to move your library to a new computer.
1. In the iTunes app 
on your PC, choose File > Library > Organize Library.
2. Select “Consolidate files.”
3. Files remain in their original locations, and copies are placed in the iTunes folder.
Back up your library and media files
Important: It’s highly recommended that you create a backup of your library.
By default, the iTunes Media folder is stored in your iTunes folder:
[User folder]\Music\iTunes\iTunes Media
1. In the iTunes app on your PC, choose Edit > Preferences, then click Advanced.
2. Note the location of your iTunes Media folder in the “iTunes Media folder location” section.
3. Quit iTunes.
4. Navigate to your iTunes folder in File Explorer.
5. Drag the iTunes folder from its location to an external drive.
We recommend the steps above because they will show you how to move your iTunes library to an external hard drive.
If you ever need to restore your iTunes library from your external drive, then follow the steps below.
You can restore your iTunes library from your external drive to a computer. If you’re restoring an iTunes library from a different computer, make sure your new computer has the latest version of iTunes.
1. In the iTunes app on your PC, choose File > Exit.
2. Locate your external drive (in File Explorer), then drag the iTunes folder you backed up earlier from your external drive to your internal drive.
3. Important: It’s highly recommended that you put the iTunes folder back in [User folder]\Music\iTunes\iTunes Media.
4. Hold down the Shift key while you open iTunes (go to Start, then choose iTunes > iTunes).
5. Click Choose Library.
6. Choose the iTunes folder that you dragged to your computer in step 2, click Open, then choose the iTunes Library.itl file inside.
Please do not hesitate to reach back out to the community if you have other questions.
Thanks for using the Apple Support Communities.
Cheers!
