I went through the exact same thing with my daughter who is now 8 months old and has been sleeping on her own and through the night from about 5 1/2 months (which is when I finally was at the end of my rope). I'm afraid that there is no easy way to separate from co-sleeping and their will be crying. There are definitely things you can do to make it a little easier like starting earlier than I did 

I loved co-sleeping with my daughter but I like you was attached to my baby pretty much 24/7. It really started to wear on me and I wasn't getting the rest that I needed. Don't get me wrong, I am glad that I did co-sleep...my birth was traumatic ending with an emergency c section and a baby with a fractured skull who needed surgery to correct. I wanted to be near her at all times to keep an eye on her.

The best thing I can tell you is what I did and hope that it works for you too.

1. Try to get on a schedule - Baby's awake time is usually anywhere from 1 1/2 hours to 2 hours until they get a little older. Look for signs of tiredness and put them to bed then. I usually try to nurse when baby wakes up but if you have to nurse before sleep make sure they do not fall asleep or else they will not learn how to fall asleep without a crutch/prop. Not as easy as it sounds but worth it in the long run.

When you do finally put them to bed and your baby cries, pick him or her up, give them a cuddle and say it's sleepy time. Leave and come back and repeat every 5 to 10 minutes until they fall asleep. This will be the most difficult thing you will have to do and may last quite a long time. After all, who wouldn't want to be rocked or nursed to sleep and have a warm body beside them. If after an 45 minutes - 1 hour it's still not working, get the baby up and give yourselves a break and try again a little while.

2. Bedtime routine - make sure you have a consistent routine for the end of the day to trigger that it's a nigh time sleep instead of a nap. I always do quite playtime, bath, book, nurse then bed.

This is really the short version but these two things helped a lot. I also read several books, the best were Healthy Sleep Habits, Happy Child and the Baby Whisperer.

Some advise that I took to heart was that your baby is going to cry when they don't get what they want, it is up to us to make sure they get what they need and sleep is one of those things.

Also, I read an article to other day about sleep that said we talk a lot about the methods for getting our child to sleep and maybe we should talk more about the end results. Do what works!

This was not easy but I am so happy that we are both getting the rest we need. Hope this helps.