Doubt , for Laurentius

I can not find this npc Laurentius order to acquire Magic for my Pyromancer
I passed through the sewer in the beginning, but the door is closed warns that it can not open the other way.
I'm in the forest where the giant has durmindo, already passed this npc?
and how to get to do it?
the butcher has to go, where is it?
Help , tanks

Have you found the butchers yet? They are at the start. At the first one (with the dogs), kill him and go cross the water. Turn left when you get back to dry land and you go into a room with barrels. Laurentis will be there. Break the barrels, talk to him. Leave the room and another Butcher will attack you. Kill him and go back and talk to Laurentis.

not found, they are at the beginning of where?
I saw in the videos that door open sewer ta wherever he goes and has the first mouse, but for me ta closed.

You have to beat the Capra Boss in the lower burg. You get the key to the Depths.

You'll have to defeat the Capra Demon at the lower Undead Burg. Once it's defeated, you get the key to the Depths. The door is to the right of the Capra boss room, down the flight of stairs. Inside, there'll be 2 butchers, clear them and save Laurentius. Try not to attack the barrels, instead, roll into them.

Once that's done, he'll be in Firelink. =)