Desoldering/soldering 1/4" chip with eight pins
This is easy to do.

Tools:


Soldering iron with fine tip.
Fine solder (0.5mm)
Tweezers
Solder wick
Alcohol and a small brush
Magnifying glass


Note that I do not include flux in the list.  It isn't needed.

Remove parts


Flood all pins in solder.  That is, put solder on the four pins on each side such that all four pins are covered in a puddle of solder.
Have a pair of tweezers ready in your left hand.  Hold the soldering iron in your right hand (reverse if you are left handed.)
Lay the soldering iron flat to the table - it should be nearly horizontal.
Use the length of the tip of the soldering iron to heat all the pins on one side.
Grab the part with the tweezers - stick the tip under the housing.  Like you would hold the part flat between your finger tips.  Keep the heat on the solder.
Move the soldering iron from one set of pins to the other - quickly.
Heat the other four pins so the solder melts.
Because of the big puddle of solder, all 8 pins should now have liquid solder over them.
Pick up the part with your tweezers.
Remove excess solder from the pins with solder wick (if needed.)

Remove the dead one first for practice, then do the good one.


Reinstall good part


Use solder wick to remove the solder from all 8 pads.
Put solder on one pad.  A pad on the corner, not  one in the middle. (Pin 1, 4, 5, or 8)
Use your tweezers to put the part in place.  Line it up so all the pins are straight over the pads.
Apply the tip of the soldering iron to the pin over the pad you put solder on.  Press down lightly so that the pin sinks into the solder and onto the pad.
Remove the iron.  Let the joint cool.  The part is now held in place by one pin.
Get a small blob of solder on the tip of the iron.
Use your tweezers to straighten the part so the pins are really lined up properly.
Apply the blob of solder to a pin and pad diagonally opposite the first on you soldered. (If you did pin 1 first, then do pin 5 now.)
The solder should connect pin and pad.  Remove iron, let the joint cool.  Remove tweezers.  The part is now held down by two pins.
Use your iron and solder to solder the other six pins.
When the other six are done and cool, go back and resolder the first two (they were poorly soldered because proper technique for soldering couldn't be followed with them.)
Clean up any excess solder with solder wick.
Cleanup excess flux with alcohol and a brush.
Inspect with a magnifying glass, resolder if needed.
Test device.


Done



When soldering the pins, many folks will recommend "drag soldering" in which you use loads of flux and a lot of solder to "smear" solder on all pins by dragging the (heavily) solder coated tip down the the row of pins.

I just solder them one at a time.  It's easy enough, and I always know that every pin was soldered - even before inspecting.