Uh...I don't see what's this talk about it being dangerous. He is only replacing the power cord - the same cord he already touch when setting up the PC, taking the picture of the cord, etc. Suggesting him to get a new PSU requires him to open up his PC case and unplug various of connectors, as well as potential compatibility issues if he purchase a PSU for a Dell that may have proprietary connectors.
OP, it seem the Philippines uses a NEMA5-15P plug as their standard. You only need to purchase a new NEMA5-15P to C13 power cord - like this: https://www.amazon.com/Standard-Computer-Power-Cord-NEMA5-15P/dp/B00BBDKX1Q