When they are old enough to start weaning (no sooner then 8 weeks) I'd slowly start dropping one bottle at a time, give them atleast a week between before dropping another bottle. At 5 weeks my kids are still on 4 bottles a day, I might cut them back to 3 at 6 weeks, but most likely they'll be on 4 until 8 weeks old, then cut down to 3 until 12 weeks, then I start the weaning process.
Are they being offered hay, grain, and water? If not you need to start, and I wouldn't even think about starting the weaning process unless they are already eating hay and grain well. If you have a friendly older goat they can be with the easiest way for them to learn is to be taught by another goat.