20 ton jack, available for rent ussually. I use a 6x6 and a steel plate on the bottle jack so it does not compress into the wood.
Lots of things are going to go snap, crackle and bang....make sure someone is with you.
I would get the carpenter back if you are not to sure what you are doing.
Make sure the column you are fixing is sitting on a new footing if it was moved over. The column could also be sinking, and adding a plate will not do much.
Simpson Strong-Tie - Helping to Build Stronger, Safer Structures
has plenty of good column retrofit products available also.