I believe hand lapping is best left to people that know what there doing. Kinda like open heart surgery, but if the patient dies, its just a barrel.
If you must, there are several websites to guide you, just do a google search for 'HAND LAPPING BARRELS'. Most of the websites start by telling not to do it :lol:
This is the extent of my knowledge on handlapping a barrel.
It involves alot of equipment that I dont own, and I doubt that you do too. You never said you were a gunsmith or had alot of tool and die equipment so i'll just stick with this assumption.
I know that lilja has worked out a way to lap parallel to the bullet travel, which keep their barrels from grabbing jacket material therefore increasing accuracy. If I were you I'd leave it to the guys who've done it before.
Well, basically the rifle is 'slugged'. Then the slug is roled in diamond lapping compound, fitted on a guide rod, and worked though the barrel taking out the tight spots.
There is also 'fire lapping' where a bullet with lapping compound is fired through the rifle.
Polishing your bore is not that complicated. Many people use JB past or even flitz polish. It is a lot of hard work by hand, but doable. It may not be exactly the same as hand lapping you get from a custom bbl, but it helps fowling. For more info go here http://www.varmintal.com/ think this is where I found out about it a few years ago. At any rate he is a retired engineer and has lots of useful info.