Placing tiles and blocks

Regardless of weather you want to edit the tilemap/blocks or chunks there are two ways to do such

The first way is to use radio boxes and tile/block select slider. Once you have what you need left click on where you want your specified tile to go

The second way is to right click on a tile this will draw a blue box around the tile now when you change the radio boxes or tile select slider it will directly affect that tile. To exit this mode left/right click on the same tile.