An explanation on the second picture.... My house is about 30 years old. It was the house that the community developer built for himself. So -- there's a ton of features that came with the house that we just can't figure out of even find :P
For instance -- in the second picture there's 3 PVC tubes that go into the ground... don't know where they go - but they're there. The house even has a connected cabana house. It's connected to the structure, but you can't walk through the house to get there. Funny thing is -- there's no record that it was built.... So that's why there's a lot of photonotes about unknown things :P
Step 1: Acquire Components
You'll also need a replacement filter. These can get expensive. Locally, we were looking at $400 + a required $75 installation fee.
Not wanting to pay that much, I (given the task of finding and installing a filter) turned to eBay.
Neely's Pools is the eBay store I bought from. The service was great - talked with them over the phone and shipping took just under a week going from Oregon to South Florida. In return for their service, I'm recommending them ;)
Another thing to consider about replacing a filter is branding. I'm not one that likes to be brainwashed by branding. In this case, finding larger brand for replacement parts and cartridges is a VERY good thing ;)
I ended up with a Hayward C17502. It has 175 sq.ft. of filtration area and a 2" female threaded connection.
My system uses 1 1/2" piping so an adapter is necessary. Additionally, it is a good idea to go for a bigger diameter pipe (as opposed to smaller) for your filter. This slows the flow across your filter and reduces head loss.
Step 2: Remove Old Filter
I used a reciprocating saw to cut the old pipe away. I also needed to disconnect an old oil furnace water heater. Be careful as there should be some water in the system. Allow the water to drain. Be sure to leave space to couple with the existing system.
Once all the piping is cut at the appropriate locations, remove the old filter.
Step 3: Rough in New Filter
Next, rough cut your PVC tubing and assemble without glue.
Step 4: Fine Tune and Cement (glue)
After the assembly is cemented together, allow to cure for the recommended time (see your cement can). After the cement has cured, fire up the pump and pressure test.