Sorry but this Blog is backwards. So start from the bottom.
This is what the finished product should look like.
When cutting the carpet ,it must be cut at best an 1/8th inch longer or overlapping the hardwood. This gives you some carpet to "tuck" in between the wood and the tack strip.
The next step is to CAREFULLY cut the carpet. There is also a tool called a carpet trimmer which is much safer but can easily cut the carpet too short if you don't cut slow.
Cut the padding back far enough so your lenght of tackstrip can be put in place about1/4 inc from the turn board at the door way.was in the picture.

This set of pictures will show you how to finish your new hardwood floor to the existing carpet. I get a few calls a month asking me to send some one out to tuck the carpet to their new hardwood. I am going to try and explain the steps taken to finish this.