Just installed my bbk lt myself... was a lot easier than I thought it was going to be.
I pulled the plug boots and set them on the engine. Removed the mass air and tubing /w air filter. Removed the air pump hoses. Then I undid the mounts, one bolt you can get at easily from under the car on each side. I put a 2x4 under the oil pan and jacked up the engine about an inch and half. Then you can just push the engine to one side while sliding your manifolds in. The passenger side was easiest, coming in from the top. The driver side you have to snake it up from the bottom. I ended up snaking part of it up and hanging it on a spark plug and moving to the engine back to pull it the rest of the way up.
Also, in order to get the gaskets in, you need to put the 1st and last bolt on to let you slide the gasket in. This proved to be harder than I thought, so I just installed a couple middle bolts, to help align the header... then put the 1st and last bolt in and removed the middle ones. That allowed me to drop the gasket in and finish up.
Also, my bbk hpipe did not line up at all (/w cats), ended up driving to exhaust shop and paying $100 to have my hpipe, flow tubes, mufflers, and tails welded up.