That's an annoying format that you have to deal with. You can split each line and output things in fastq format with:
Code:
awk -F ":" '{printf("@%s:%s:%s:%s:%s\n",$1,$2,$3,$4,$5);print $6; print"+"; print $7}' foo.txt > foo.fastq
You'll need to rename "foo.txt" to whatever your files are actually called.