Try the following steps to DIY ar.
1. Stop the main water supply.
2. Use crocodile clamp to uninstall the old tap .
3. Apply water pipe tape (can be bought from 五金鋪) to wrap around the joint (thick and tight if you don't want to have water leak.
4. install the new tap with your crocodile clamp.
5. Turn on the main water supply and see if any water leakage.
6. Maybe to open a bottle of Château Latour to celebrate --- You DID it Buddy!