We are expecting our little boy in only a few weeks! In the interest of saving money, I almost decided that he would just have to use my daughters old car seat. I tried to find covers and all that, but in the end, there was nothing that I loved, or that would fit just right.
I decided this week, (because I am pregnant and entitled to sudden changes in opinion haha) that my son cannot ride in a pink carseat, and I had to do something about it. I decided to make a new cover my self. I went and picked the fabric I wanted and got started. Please take note, if you do this you are effectively voiding most manufacturer warrantees.
The car seat was originally pink, brown and grey. I simply removed the cover and ran it through the wash and let it hang dry. I also cleaned the base really well, just for the sake of due diligence.
I got my seam riper out and started to carefully remove the trim, keeping it in tact. I am going to recycle every part of the cover. After I successfully removed the trim I ripped the seams between all of the pieces that made up the car seat.

Lucky for me there were only 6 large pieces, and the trim that included a small piece of fabric for the top and bottom that make the cover fit snugly around the base.
Each piece was already sewed independently to the backing and batting, so I left them that way.
I traced each piece onto my fabric and cut each of the fabric pieces, careful to lay them on top of the piece they match with, so that I didn't lose track of what piece went where.
Keeping them all set in the proper places and leaving them that way, saved me time and guess work in the future!

Once all pieces were cut, I started the process of pinning them. I very precisely pinned every little curve and corner. I used every one of the pins in my collection, and I have a lot of pins! I put a pin about every inch, on every single piece.
Pinning was very challenging, the fabric is thick and there were very few straight lines. I chose to go crazy pinning simply because I was afraid that as I started to sew, that the fabric would pull and look really awkward. I was very pleased with this decision when I started to sew it, but it took a very long time to pin all of the pieces this way.
My machine could handle the thickness, but the sewing had to be very precise, and with the abundance of pins, I could concentrate on that precise line, instead of making sure things didn't shift along the way.
Again, I laid each piece out in its proper order as I completed pinning each one.

When I started sewing I turned each piece upside down, and sewed very carefully along the edge of the padding.
I was very careful to maintain an even and precise stitch, very close to the edge. The intention of this stitch is only to hold the new fabric on the top of the old. Later when I connect the pieces, this stitch will be hidden, but is the start of the straight lines I will have to maintain later!
In some places I trimmed the access fabric that showcased my lack of tracing ability. :)

Once I finished the sewing and removed all of the pins, I used my nifty exacto knife to cut the slots for the buckles.
I used a zigzag stitch to go around each slot. After the first one though, I adjusted the stitch to make it thicker and more secure.
When I started to sew the pieces together, I worked on them one at a time. I pinned them like crazy to make them perfect again, and then sewed them together with a stitch that followed the seam that was already there.

I put together the bottom three pieces, then the top three pieces. Then I sewed the top to the bottom. It was a little tricky, but thankfully I used a million pins, so I didn't have to worry about the seams matching up, and making a straight line.
The trim was a nightmare! I could not use my pins to hold the trim in place, the fabric was too thick, and the trim was too thin. I got out some old ugly thread and a needle and loosely sewed the trim in place by hand all the way around.

With everything else fitting right and sewn perfectly, I got on my machine and stitched all of the way around the trim. For sure, the hardest part of this process. I bent one needle, and learned some major lessons about my machines functionality. I removed my ugly stitches, and you can hardly tell that I struggled so much.
The end result was the exact car seat that I wanted. It matches his blanket, and room decor. I am pretty proud of myself and a job well done!