How to swap columns in such a file?

It can be done with awk using " as the field separator. But doing that, you must remember that $1 is empty, $2 holds the first string, $3 is the space between strings, $4 is the second string, etc. Also, it's more reliable to swap the two strings instead of just printing all the fields and hoping you put enough $ns. Bearing these in mind, the following should work:

awk 'BEGIN{OFS=FS="\""} {tmp=$4;$4=$6;$6=tmp;print}' input_file >output_file