How hard and where can i find some info on converting an 18" dishwasher cabinet slot into a 24" slot?

I need to do this cuss the part to fix my 18" no longer exist and we want a cheaper 24" dishwasher. I looked up how to install kitchen cabinets and i got an idea of what is there and what to remove just no idea what all i am getting myself into before i butcher my cabinets. At the moment a 24" inch dishwasher is nearly 100$ cheaper than an 18" model.

you might have to move some cabinets, just make the available opening 24 inches, plus one inch so you have room to maneuver it into place

Its fairly straight froward: get a tape measure, figure out what size cabinet (and or scribe strips) you need to replace the now to large cabinet and go from there. Check very very closely for all the fasteners holding the old cabinet in place (to countertops, to wall, and probably the the face frame of the other cabinets) once those are out the old cabinet will wiggle out of line (perhaps with some difficulty), install new cabinet and needed scribe strips), then re-install the new DW.

Considering all that $100 bucks sounds a cheap way 'round.

I don't blame you wanting a bigger dishwasher. We have three children and the dishes pile up quickly. But as the above answer said, it is cheaper to spend the $100. To make the opening wider you either need to spend money finding 6" narrower cabinet that matches. Good luck there. Or you can rearrange the cabinets, which means new countertop. More than $100. Or you try to cut down a cabinet. The basic box and frame would be possible, not easy with basic tools, but possible. But the doors and drawers would have to cut down, too. Depending on the style, you can't or shouldn't do it without a shaper or at least a router. And you need specialty bits.

If you decide you can't live without a 24" dishwasher, and like I said, don't blame you all, the best option MAY be to rearrange the cabinets and get a need countertop. I say may, if the flooring butts up to the cabinet, not under it, then you get into flooring issues. Plus it may not even be possible if the wall the dishwasher is short. Usually you have a 36" sink base, 24" dishwasher space, 12" on either side of that. If an L- or U- shape kitchen another 24" on either side of that.

$100 isn't sounding too bad, unless the 24" is absolutely needed.

Honestly, if this was my situation, I would bite the bullet and spend the extra $100.00 and not butcher my cabinets unless you need the larger dishwasher. If you don't forsee needing the larger one....then spend the extra money and get what fits.
You can check too for that manufacturer, selling returns or damages...sometimes damages are only a slight scratch, and customers change their minds and return items...can get a big break on the price if you check it out....

You first need to determine if you can simply uninstall existing cabinets and reinstall to give you the required new opening size. Can your existing cabinets be slid the required 6" to make room for the new dishwasher? If not which cabinet on either side of existing hole will be missed the least? One other simple option is to also purchase a matching smaller base cabinet at your local home improvement store. Then you would just have to deal with making a smaller counter top. Each step will lead to one more unexpected thing until complete.