Changing taps can be very easy if its like for like. By that we mean if they're the same size. For example replacing a mixer tap for a mixer, or two single taps renewed for two single taps. Maintaining and repairing taps is also relatively easy. Their are many styles, shapes and colours but they all work the same way and do the same job.
Removing and Installing like for like:
Turn off water supply to both taps.
Drain the water from pipework to taps.
Place a container under the pipework to catch any spills then undo both tap connectors (where pipe meets tap).
Undo securing nut holding taps in place (the big nut stopping it from wobbling).
Remove the taps from the appliance.
Insert new taps into position of old taps with the new washers provided.
Fit new securing nut and tighten, making sure that the taps are square and have not swivelled around.
Reconnect tap connectors and tighten, again making sure the taps haven't turned while you were tightening up. If they have just re-adjust until they are straight.
Turn the water supply back on and check for leaks.
Tap problems and remedies:
There are two main problem that you get with taps.
1) If is leaking out of the spindle (waters coming out of the head rather than the nozzle) it will need to be repacked.
2) If the nozzle/spout is leaking, its noisey when you use it or the flow stop starts then you need to replace the washer. To do this you need to:
Turn off the water supply to tap.
Drain off the water in the pipework.
Undo the tap head, usually by carefully flicking off the top cap and undoing the screw.
Remove top to expose tap body or "guts" as they are sometimes called.
Undo the body of the tap with two sets of grips or whatever you're using (you turn the big nut at the bottom while holding the tap still with the other set).
Remove the body completely from the tap to expose the washer, pull off and replace with new. Assembley in reverse order (put back together).
Fill and check for leaks.