First thing, since this is a structural
issue, it needs to be done in accordance
with code. Talk to some contractors to
get an idea what it really needs and what
they'd charge. I've done a little leveling
with a 12 ton hydraulic jack. It's
definitely not something to try if you're
not exactly sure what you're doing. It's not
something I can tell you how to do via e-mail. You have to start with the lowest
point, and raise it as much as you can
without distorting the structure too much,
then raise other points around it, always
supporting everything properly, and never
lifting anything too much at once. When you get it lifted, then you have to build a
proper footing and cripple walls, and put in
whatever is required under the middle of it.
Check with your building and safety
department to see what they allow an owner-
builder to do.