Ok, if you're going for a clean up in place (no draining), do this:
KILL the ALGAE
1. Add plain 6% bleach each evening, as needed to keep your OTO kit in the DARK yellow / orange range.
2. Take the cartridge OUT of the filter. Order new cartridges, if you have none.
3. Test your pH BEFORE adding more chlorine, when OTO level is medium yellow to clear. If your pH is above 8.0, add ~1/4 gallon of muriatic acid at a time. (see link in my signature)
4. After the pool turns cloudy gray or blue, BRUSH the pool completely, to stir up any algae on the bottom. But, add bleach just BEFORE brushing. If the pool turns green after brushing, add another 2 gallons of bleach.
5. Continue till the pool is cloudy blue or gray even after brushing.

REMOVE the ALGAE
You have two options here: you can vacuum to waste, using a siphon. To do so, you'll need a vac head, pole, and hose that will reach from the center of the pool to the ground outside the pool. OR, you can filter it out. The Intex filter cartridges do NOT work well for this. I just spent an hour on the phone with Unicel's national product manager, and he assures me their cartridges should work much better than the OEM ones, AND that two cartridges should last all season. (Intex says to discard their cartridges every two weeks!) To use the filter method, you need (2) new Intex cartridges, a covered 5 gallon bucket or trash can, and some TSP.

Here's the process:
1. Install new cartridge
2. Remove when flow drops; install 2nd cartridge
3. Hose off the dirty cartridge
4. Mix 3 gallons of water with 2 cups of TSP. Add 1/8 cup of bleach.
5. Put the dirty cartridge in the mix, and cover.
6. When flow begins to drop, remove cartridge from soak, and hose off.
7. Place cartridge in bucket fill with fresh water for 15 minutes (you don't want TSP in your pool!)
8. Remove and rinse again. Install rinsed cartridge in filter.
9. Hose off dirty cartridge, and restart process.

Here are the products you need:
1lb Savogran 10621 Trisodium Phosphate (TSP) @ Amazon
Unicel C-4607 Replacement Filter Cartridge (Easy Set Size A or C) @ Amazon
You should be able to get TSP locally at Ace Hardware or Lowes, if you prefer. Often it will be in the paint section. However, if you try to buy the Unicel cartridges elsewhere, be very, very careful. Some imported cartridges are being sold as Unicel replacements, but the descriptions are being written very deceptively.