OK so what you need to do is this: Google "Pokemon white 2 abyssal ruins map". Then get the TMs/HMs Strength and Flash and make a pokemon learn them. Get to the middle of the first floor using the passage shown on the image you googled. Then do the same for the next floor. Use either Strength or Flash at the moving block. Not sure which is first; use the one that didn't work there on the next floor.
I would advise making a whole bunch of trips like this; first get treasure on 1st floor. Torrent will get you. Then do same with second, etc. It will be a hassle, but you will make a ton of money.
Hope this helped and sorry for the lengthy description!