In my former career I reviewed lot line adjustments for another City. Lot line adjustments are covered under State law as an exemption from the subdivision code. The key is to show that what you are proposing is really a lot line adjustment between two lots, and not a subdivision. The other bar is that you cannot make a situation less conforming. So, in short lot line adjustments are really not hard at all if you have a clear concept of what you want to accomplish, and hire professionals to assist you. You can talk with a City land use planner at the City for specifics. I would be glad to take a look at your situation if you want to send me an email with the particulars.