Needs to be out of the car to do the main bearings, as you need the crank out which is bolted to the flywheel.

Bottom end is an easy re-build as long as you stick with in tollerance whch are given in the haynes manual.

basicly, strip the block down, measure the crank jurnals to see if there worn to much, if they are, a re-grind is needed and over sized bearings are required. Same for the bores. measure them up and see if there have worn to much, if so a re-bore is needed and over sized pistons and rings required.

if all ok, Hone the bores so new rings can bed in. lightly polish crank jurnals using fine wet and dry. the refit bearings making sure they go the right way round.
also the pistons and bearing caps etc all have to face the right way and be in the same order they came out of. Worth marking bits up when removing them.