How do I make swapping stuff?

So this is my first game in which there are sprites which have the Drag and Drop behaviour but how can I make the swapping the tiles? Like you pick a sprite and when overlapping another and you drop that, the dropped one gets placed on overlapped one while the below tile sets to the location of picked tile?

Also since there are 3 types of tiles, one type of tile is static but other 2 are randomly placed in a grid, how can I do that?