Can I add a screen to an existing install?

I have Ropieee running nicely, and would like to add the touchscreen. Do I have to start again with a new installation, or just cable the screen in and reboot?

I believe from past posts by @spockfish that the display software is only installed at the beginning if the hardware is detected then. It will take you less time to re-flash than you think.

Thanks - I’ll reflash then.