Rugs, Carpets and Carpeting - How can we do baseboards before carpet if tack strip is already down?

We tore up the carpet and the pad in our main room to do some remodeling. We originally had lawyer block panelling in our main room. We removed it and replaced it with drywall. The tack strip stayed down from where the original carpet laid.
We want to put the baseboards on before the carpet comes, which is in three days. However, the question is primarily about the tack strip. We would rather not remove it...but the distance from the new drywall is different than from the old panelling. How far is the tack strip supposed to be from the wall? Ours is 1/2 inch away from the wall and we haven't yet added the baseboard.
Now, do we add the baseboards first or after carpet? If we add them before the carpet? How far do we go up? (Going up a 1/2 inch like other messages have suggested doesn't allow any space between the baseboard and the tack strip.) So how do they tuck it in?
Please help?

Go ahead and take the old tackless out and install the baseboard 1/4" to 3/8" above the floor. 1/2 inch is a little high for my taste, and unless the chosen carpet is really thick there would be a void between the two.