Since coil stock to do the job is almost $100.00 a roll now, and going up agin next month, a break to bend it cost about $1700.00, (yes you can rent one but the learning curve will kill you on time and materials,) tin snips I guess would cut it but a real siding person would use special snips with longer handls, then your going to need several differant seam tools at $58,00 a pop, and by the questions your asking, I'd strongly suggest hiring this one out. Every year we have at least 2 or 3 jobs to remove all the DIY siding and have to redo the whole job.
I've never seen a DIY cut or tab over the trim around a window or doors right, it's nailed to tight, not nailed in the middle of the oval holes, cut to long or to short, run in the wrong direction. ECT.
If the plan is to leave the old wooden siding in place all the window trim and sills will need to be built out before they get wrapped, Z moulding added over the windows and doors, Fan fold foam installed over all the wallls.
This is a one shot deal, done wrong and all the seams show, it buckels, or unlocks, wood rot starts behind the siding from leaks.