The Cycle Workshop is just one part of a significant cycling specific advice, information and shopping resource produced and managed by e-cobr marketing.
Having removed both cranks from the bike start with the chain side first.
Engage the external teeth of the extractor with the retaining ring.
Once positioned in the retaining ring, place a large spanner or adjustable spanner on the extractor. You need to be very gentle with the spanner as the retaining ring is usually made of plastic, or a resin and if you are not careful, you could strip it. This one you need to rotate in a CLOCKWISE direction to remove.
Now, you need to insert to extractor on the non-chain side. To remove you rotate this one in the regular, counter-clockwise direction.
Now remove the cartridge out of the bottom bracket shell.
Replacement
Clean the inside of the bottom bracket shell with spray lube.
Again start with the chain side by screwing the retaining ring in partially, to make sure the threads are clean. Coat with anti-seize, or copper grease, if appropriate.
Screw the retaining ring in about 2/3 of the way with your fingers, making sure it goes in straight.
Now switch to the non-chain side of the bike. Make sure the cartridge is clean and again apply anti-seize, or copper grease, if appropriate. Screw it in as far as you can with your fingers.
Now use the wrench to tighten it into position. It should be flush with the bottom bracket shell. Remember to screw this side, the non-chain side, in clockwise.
Now go back to the chain side. You need to tighten the retaining ring until it touches the end of the cartridge. This will lock it into place.