Upgrading storage of MacMini8,1
Hi Can I upgrade storage of MacMini 8,1, from 1 TB to 2 TB.
Mac mini, macOS 15.3
No, the 2018 Mac mini's internal storage drive is not upgradable.
If you need or want more space, you will need to use and external HD or SSD.
Free up storage space on Mac - Apple Support
To free up a lot of space, you can move your Photos, Music, Movie Libraries to an external HD or SSD.
Move your Photos library to save space on your Mac - Apple Support
Change where your music files are stored on Mac - Apple Support
Move your iMovie for Mac library - Apple Support
To protect your off-loaded Libraries, it is wise to backup the Libraries using a second external HD or SSD.