My partner of 6 years and I want him to adopt my daughter of 5 yrs, he has been as good as a father and been with us since I was pregnant with my daughter and ever since. Her biological farther has never bothered with er and is;nt even on the birth certificate.
They have a brilliant relationship together and I would like to make this officially legal, How would I go about this?

To make it legal, you first must be married to your partner. Then you need to properly petition the Court for the adoption.

First there is a great sticky at the top of the main family law page to give you a lot of help.

If you are in the US, most states ( not all) will require you to be married for at least one year before they allow adoption. Some states don't require the marriage but accept a long term relationship.

Next it may even be harder since he is not on the birth certificate, you will have to have his still sign over his rights but now may have to also pay for his DNA test to prove he is the father.