How do you extract and replace bolts going into concrete?

I am replacing a deck and I need to pull out some of the bolts that attached the old ledger board to the house. What is the proper way to do this without damaging the concrete too much?

if the bolts are hammered in, dont try to remove them!!! anchor bolts are designed to wedge themselves tighter as they are pulled out, thus giving the ability to tighten a nut without pulling out the bolt.advice: if the bolt threads arent too damaged, try to repair the bolt with a thread die of the correct size and thread taper,found in tap and die sets or as a single tool at most home improvement centers.worst case:if the threads are too far gone, i recomend cuting it off and seting a new anchor.firstly,determin the size bolt needed,purchase new ones at any home improvement center, then use a hammer drill with the corresponding size masonery drill bit to make a new hole a few inches from the old one,at the correct depth(hammer drills can be rented for a minimal cost)next,start a nut on the new bolt(about 3/4of the nut)this prevents damaging the threads, then carefully hammer the new bolt into the new sure to clean the hole of dust and debris first to prevent slippage.remember,when these anchor bolts are set, they will NEVER come out!!!! i sugest getting bolts that are several inches too long, then cuting off the excess after your ledger board has been attached.i hope this helps, and happy building!!