Starting off from one column it can be easier to add a line in between the two sections you want in separate columns, this seems to break up the sections and make them easier to move.

Click and drag either section of text next to the other. Note the thick vertical line showing where the section will go should only be about as big as the block of text, if it's taking up the whole page it's going to push everything to the next column, if it does this you can just drag and drop until it gets to the right place :)