You can find Part One Here
Let me start off by saying that this is how I did it and it worked for me; however, I tend to kind of make things up as I go. There are several tutorials out there that you might find more helpful than the way I did it.
To replace the spindles I started by removing the old ones. To do this I took my Jigsaw and cut right through them on the smallest part of the spindle. -
Next I cut the top of the spindle off (where there is no varnish, making it flush with the rail when inserted) with my miter saw and used liquid nails to glue it back up inside the top rail. I did this to have some solid wood for my screw to go into when I put the new spindle in. -
To remove the bottom of the old spindle I had to unscrew it off of this screw -
We purchased our new square spindles from Home Depot for about $4 each. I cut them to the desired length I needed them to fit between the top and bottom. Next, I found the center on one end and drilled a hole into it so that it can be screwed into the screw pictured above.
(yes, I do know that I didn't quite hit my center below :)
Lastly, I used my Kreg Jig to make a pocket hole on the opposite end of where I drilled the other hole:
I added Liquid Nails to both ends and screwed the spindle on to the bottom screw. Once in place, I put a 2 1/2 inch pocket hole screw in the top attaching it to the top railing.
After doing this a gazillion times, you have new spindles!
I caulked the spindles on the top and bottom, and used wood pocket hole plugs and wood filler to fill in my pocket holes.
I painted the newel post, bottom rails, and spindles a latex white in satin that matches the rest of the molding in my house.
For the top rails and hand rail, I sanded them and then made sure I got everything wiped down very well. After covering and taping off everything but the rails, I used General Finishes Gel Stain in Java and General Finishes Poly/Acrylic Satin (you can also buy it at Four Chairs in Lindon if you are local).
I saw and used a great tutorial from Confessions for a Semi-Domesticated Mama on how to use it.
This stuff is seriously amazing to work with, and it goes a LONG way too!