Installing a camera on the ceiling could be as easy as pie. Check out the links below according to the Reolink cameras you have and try to install one by yourself.
Applies to: RLC-420, RLC-420-5MP, RLC-422, RLC-422W, RLC-520, RLC-520A, P325,RLC-522, RLC-542WA, RLC-820, RLC-820A, P335, RLC-822A, P433, RLC-824A, RLC-833A, P434, RLC-842A, RLC-1224A, P345, D400, D800, P335C, CX820, ColorX Series P335X.
You can refer to this article to install RLC-520, RLC-520A, RLC-522, RLC-820A, RLC-822A, RLC-824A, RLC-833A, RLC-1224A, D400, D800, and CX820:
How to Mount RLC-520/RLC-520A/RLC-522/RLC-820A/RLC-822A/RLC-824A/RLC-833A/RLC-1224A/D400/D800/CX820
You can refer to this article to install RLC-420 and RLC-420-5MP:
How to Install/Mount the RLC-420
You can refer to this article to install the RLC-422 series, RLC-542WA, and RLC-842A: