This is a great resource for doing a line by line comparison and contrast between the two documents. This is particularly helpful given that in the Preface to the 2LBCF the authors state that they have purposely copied, at points, word for word from the WCF in order to demonstrate where they are in agreement, in order to establish themselves as part of the historic stream of orthodoxy:
. . . to fix on such a method as might be most comprehensive of those things we designed to explain our sense and belief of; and finding no defect in this regard in that fixed on by the Assembly, and, after them by those of the congregational way, we did readily conclude it best to retain the same order in our present Confession; and also when we observed that those last mentioned did in their Confessions (for reasons which seemed of weight both to themselves and others) choose not only to express their mind in words concurrent with the former in sense concerning all those articles wherein they were agreed, but also for the most part without any variation of the terms, we did in like manner conclude it best to follow their example in making use of the very same words with them both in these articles (which are very many) wherein our faith and doctrine are the same with theirs; and this we did the more abundantly to manifest our consent with both in all the fundamental articles of the Christian religion, as also with many others whose orthodox Confessions have been published to the world on the behalf of the Protestant in diverse nations and cities. And also to convince all that we have no itch to clog religion with new words, but do readily acquiesce in that form of sound words which hath been, in consent with the Holy Scriptures, used by others before us; hereby declaring, before God, angels, and men, our hearty agreement with them in that wholesome Protestant doctrine which, with so clear evidence of Scriptures, they have asserted. Some things, indeed, are in some places added, some terms omitted, and some few changed; but these alterations are of that nature as that we need not doubt any charge or suspicion of unsoundness in the faith from any of our brethren upon the account of them. [emphasis mine]This chart does an excellent job of showing forth their changes. One of the differences that is key in understanding the different positions is found in chapter 7 where the 2LBCF does not contain any statement about the covenant of works. Although the major differences can be seen later in dealing with the topics of church and sacraments, these differences seem to stem from the differences in their respective understandings of covenant theology, which hinges on the rejection of the covenant of works.