To change the default location where Ollama saves its models you need to set an environment variable called OLLAMA_MODELS to the desired directory
Open a terminal and run systemctl edit ollama.service
Add the line Environment=“OLLAMA_MODELS=/path/to/new/location“ under the [Service] section
Save and exit the editor
Reload and Restart
Run systemctl daemon-reload
Restart Ollama with systemctl restart ollama