If you can replace a light bulb then probably you are ready to take it to the next level…
This is a very simple task, here are the steps you should follow. The most important thing is to disconnect the main power to be sure that there is no electricity running. If you need to use some electric tools to mount the spotlight (i.e. a drill to make the holes for an anchor) you should first unmount the old spotlight, isolate the wires, put the power back on to drill the holes and then put it back off to do the final wiring and mounting.
REMEMBER, SAFETY FIRST!
Step 1: Turn the main power off. Unmount the old spotlight, most likely you will have 2 wires, one blue (neutral) and one brown, black or gray (line). In addition, there could be a yellow-green one, the protective earth (this colour code is valid for the EU).
Step 2: Mount the spotlight anchorage to the wall.
Step 3: Connect the two cables to the pvc socket following the colour scheme, if needed cut the tip of the cable and peel 5mm of the plastic cover off, so that you have a solid end to tighten the socket in. After tightening all of the screws pull the wires genlty to make sure that they are fixed properly. If you do have a earth cable you can fix it in the proper socket, if not provided you can isolate it with a plastic cap and store it in the spotlight’s base.
Step 3: Fix the spotlight to the anchorage and mount the light bulb. Turn the main power back on.