You can remove 4'5'8 from the far right cells in the middle box. With the 3 and 6 solved. You know that those four cells (2, 4, 5, and 8) only contain that, so the other ones (the 3 cells in the right) cannot.
Also, the top line from the bottom group.. the 4,5,8 trio is there too. That will clear out those numbers from any cells that may also have 4,5,8 on that line.
Bottom row 2&7 are in there twice. Remove 2&7 from all other cells in this row. Now in bottom middle 3x3 you have twice 5&8. Therefore bottom left of bottom middle 3x3 is 9.
And off you go...